refactor: Remove PyContracts usage. (#27887)

* refactor: Remove PyContracts usage. We have not used PyContracts in a while and it is overhead we don't need in edx-platform. https://openedx.atlassian.net/browse/DEPR-147 * chore: Updating Python Requirements (#28018) Co-authored-by: edX requirements bot <49161187+edx-requirements-bot@users.noreply.github.com>
2021-06-23 18:24:06 -04:00
parent a775d5cebc
commit 29548459fa
32 changed files with 47 additions and 343 deletions
--- a/cms/conftest.py
+++ b/cms/conftest.py
@@ -11,7 +11,6 @@ import importlib
 import logging
 import os

-import contracts
 import pytest

 from openedx.core.pytest_hooks import DeferPlugin
@@ -32,9 +31,6 @@ def pytest_configure(config):

    if config.getoption('help'):
        return
-    enable_contracts = os.environ.get('ENABLE_CONTRACTS', False)
-    if not enable_contracts:
-        contracts.disable_all()
    settings_module = os.environ.get('DJANGO_SETTINGS_MODULE')
    startup_module = 'cms.startup' if settings_module.startswith('cms') else 'lms.startup'
    startup = importlib.import_module(startup_module)
--- a/cms/wsgi.py
+++ b/cms/wsgi.py
@@ -15,10 +15,6 @@ isort:skip_file
 from safe_lxml import defuse_xml_libs
 defuse_xml_libs()

-# Disable PyContract contract checking when running as a webserver
-import contracts  # lint-amnesty, pylint: disable=wrong-import-order, wrong-import-position
-contracts.disable_all()
-
 import os  # lint-amnesty, pylint: disable=wrong-import-order, wrong-import-position
 os.environ.setdefault("DJANGO_SETTINGS_MODULE", "cms.envs.aws")

--- a/common/lib/xmodule/xmodule/assetstore/init.py
+++ b/common/lib/xmodule/xmodule/assetstore/init.py
@@ -8,18 +8,9 @@ from datetime import datetime

 import dateutil.parser
 import pytz
-from contracts import contract, new_contract
 from lxml import etree
 from opaque_keys.edx.keys import AssetKey, CourseKey

-new_contract('AssetKey', AssetKey)
-new_contract('CourseKey', CourseKey)
-new_contract('datetime', datetime)
-new_contract('basestring', (str,)[0])
-new_contract('long', int)
-new_contract('AssetElement', lambda x: isinstance(x, etree._Element) and x.tag == "asset")  # pylint: disable=protected-access
-new_contract('AssetsElement', lambda x: isinstance(x, etree._Element) and x.tag == "assets")  # pylint: disable=protected-access
-

 class AssetMetadata:
    """
@@ -51,13 +42,6 @@ class AssetMetadata:
    # Filename of all asset metadata exported as XML.
    EXPORTED_ASSET_FILENAME = 'assets.xml'

-    @contract(asset_id='AssetKey',
-              pathname='str|None', internal_name='str|None',
-              locked='bool|None', contenttype='str|None',
-              thumbnail='str|None', fields='dict|None',
-              curr_version='str|None', prev_version='str|None',
-              created_by='int|long|None', created_by_email='str|None', created_on='datetime|None',
-              edited_by='int|long|None', edited_by_email='str|None', edited_on='datetime|None')
    def __init__(self, asset_id,
                 pathname=None, internal_name=None,
                 locked=None, contenttype=None,
@@ -155,7 +139,6 @@ class AssetMetadata:
            }
        }

-    @contract(asset_doc='dict|None')
    def from_storable(self, asset_doc):
        """
        Fill in all metadata fields from a MongoDB document.
@@ -179,7 +162,6 @@ class AssetMetadata:
        self.edited_by_email = asset_doc['edit_info']['edited_by_email']
        self.edited_on = asset_doc['edit_info']['edited_on']

-    @contract(node='AssetElement')
    def from_xml(self, node):
        """
        Walk the etree XML node and fill in the asset metadata.
@@ -210,7 +192,6 @@ class AssetMetadata:
                    value = json.loads(value)
                setattr(self, tag, value)

-    @contract(node='AssetElement')
    def to_xml(self, node):
        """
        Add the asset data as XML to the passed-in node.
@@ -238,7 +219,6 @@ class AssetMetadata:
            child.text = value

    @staticmethod
-    @contract(node='AssetsElement', assets=list)
    def add_all_assets_as_xml(node, assets):
        """
        Take a list of AssetMetadata objects. Add them all to the node.
@@ -253,7 +233,6 @@ class CourseAssetsFromStorage:
    """
    Wrapper class for asset metadata lists returned from modulestore storage.
    """
-    @contract(course_id='CourseKey', asset_md=dict)
    def __init__(self, course_id, doc_id, asset_md):
        """
        Params:
--- a/common/lib/xmodule/xmodule/assetstore/assetmgr.py
+++ b/common/lib/xmodule/xmodule/assetstore/assetmgr.py
@@ -13,14 +13,8 @@ Note: Hotfix (PLAT-734) No asset calls find_asset_metadata, and directly accesse

 """

-
-from contracts import contract, new_contract
-from opaque_keys.edx.keys import AssetKey
-
 from xmodule.contentstore.django import contentstore

-new_contract('AssetKey', AssetKey)
-

 class AssetException(Exception):
    """
@@ -48,7 +42,6 @@ class AssetManager:
    Manager for saving/loading course assets.
    """
    @staticmethod
-    @contract(asset_key='AssetKey', throw_on_not_found='bool', as_stream='bool')
    def find(asset_key, throw_on_not_found=True, as_stream=False):
        """
        Finds course asset in the deprecated contentstore.
--- a/common/lib/xmodule/xmodule/assetstore/tests/test_asset_xml.py
+++ b/common/lib/xmodule/xmodule/assetstore/tests/test_asset_xml.py
@@ -4,9 +4,7 @@ Test for asset XML generation / parsing.


 import unittest
-import pytest

-from contracts import ContractNotRespected
 from lxml import etree
 from opaque_keys.edx.locator import CourseLocator
 from path import Path as path
@@ -81,21 +79,3 @@ class TestAssetXml(unittest.TestCase):
        AssetMetadata.add_all_assets_as_xml(root, self.course_assets)
        # If this line does *not* raise, the XML is valid.
        etree.fromstring(etree.tostring(root), self.xmlparser)
-
-    def test_wrong_node_type_all(self):
-        """
-        Ensure full asset sections with the wrong tag are detected.
-        """
-        root = etree.Element("glassets")
-        with pytest.raises(ContractNotRespected):
-            AssetMetadata.add_all_assets_as_xml(root, self.course_assets)
-
-    def test_wrong_node_type_single(self):
-        """
-        Ensure single asset blocks with the wrong tag are detected.
-        """
-        asset_md = self.course_assets[0]
-        root = etree.Element("assets")
-        asset = etree.SubElement(root, "smashset")
-        with pytest.raises(ContractNotRespected):
-            asset_md.to_xml(asset)
--- a/common/lib/xmodule/xmodule/graders.py
+++ b/common/lib/xmodule/xmodule/graders.py
@@ -11,7 +11,6 @@ import sys
 from collections import OrderedDict
 from datetime import datetime

-from contracts import contract
 from pytz import UTC
 from django.utils.translation import ugettext_lazy as _

@@ -26,7 +25,6 @@ class ScoreBase(metaclass=abc.ABCMeta):  # pylint: disable=eq-without-hash
    Abstract base class for encapsulating fields of values scores.
    """

-    @contract(graded="bool", first_attempted="datetime|None")
    def __init__(self, graded, first_attempted):
        """
        Fields common to all scores include:
@@ -56,7 +54,6 @@ class ProblemScore(ScoreBase):
    """
    Encapsulates the fields of a Problem's score.
    """
-    @contract
    def __init__(self, raw_earned, raw_possible, weighted_earned, weighted_possible, weight, *args, **kwargs):
        """
        In addition to the fields in ScoreBase, arguments include:
@@ -88,7 +85,6 @@ class AggregatedScore(ScoreBase):
    """
    Encapsulates the fields of a Subsection's score.
    """
-    @contract
    def __init__(self, tw_earned, tw_possible, *args, **kwargs):
        """
        In addition to the fields in ScoreBase, also includes:
--- a/common/lib/xmodule/xmodule/modulestore/init.py
+++ b/common/lib/xmodule/xmodule/modulestore/init.py
@@ -13,7 +13,6 @@ from collections import defaultdict
 from contextlib import contextmanager
 from operator import itemgetter

-from contracts import contract, new_contract
 from opaque_keys.edx.keys import AssetKey, CourseKey
 from opaque_keys.edx.locations import Location  # For import backwards compatibility
 from pytz import UTC
@@ -32,11 +31,6 @@ from .exceptions import InsufficientSpecificationError, InvalidLocationError

 log = logging.getLogger('edx.modulestore')

-new_contract('CourseKey', CourseKey)
-new_contract('AssetKey', AssetKey)
-new_contract('AssetMetadata', AssetMetadata)
-new_contract('XBlock', XBlock)
-
 LIBRARY_ROOT = 'library.xml'
 COURSE_ROOT = 'course.xml'

@@ -497,9 +491,6 @@ class BlockData:  # pylint: disable=eq-without-hash
        return not self == block_data


-new_contract('BlockData', BlockData)
-
-
 class IncorrectlySortedList(Exception):
    """
    Thrown when calling find() on a SortedAssetList not sorted by filename.
@@ -519,7 +510,6 @@ class SortedAssetList(SortedKeyList):  # lint-amnesty, pylint: disable=abstract-
            self.filename_sort = True
        super().__init__(**kwargs)

-    @contract(asset_id=AssetKey)
    def find(self, asset_id):
        """
        Find the index of a particular asset in the list. This method is only functional for lists
@@ -540,7 +530,6 @@ class SortedAssetList(SortedKeyList):  # lint-amnesty, pylint: disable=abstract-
            idx = idx_left
        return idx

-    @contract(asset_md=AssetMetadata)
    def insert_or_update(self, asset_md):
        """
        Insert asset metadata if asset is not present. Update asset metadata if asset is already present.
@@ -577,7 +566,6 @@ class ModuleStoreAssetBase:

        return course_assets, idx

-    @contract(asset_key='AssetKey')
    def find_asset_metadata(self, asset_key, **kwargs):
        """
        Find the metadata for a particular course asset.
@@ -597,10 +585,6 @@ class ModuleStoreAssetBase:
        mdata.from_storable(all_assets[asset_idx])
        return mdata

-    @contract(
-        course_key='CourseKey', asset_type='None | str',
-        start='int | None', maxresults='int | None', sort='tuple(str,int) | None'
-    )
    def get_all_asset_metadata(self, course_key, asset_type, start=0, maxresults=-1, sort=None, **kwargs):  # lint-amnesty, pylint: disable=unused-argument
        """
        Returns a list of asset metadata for all assets of the given asset_type in the course.
@@ -699,7 +683,6 @@ class ModuleStoreAssetWriteInterface(ModuleStoreAssetBase):
            all_assets.insert_or_update(asset_md)
        return assets_by_type

-    @contract(asset_metadata='AssetMetadata')
    def save_asset_metadata(self, asset_metadata, user_id, import_only):
        """
        Saves the asset metadata for a particular course's asset.
@@ -714,7 +697,6 @@ class ModuleStoreAssetWriteInterface(ModuleStoreAssetBase):
        """
        raise NotImplementedError()

-    @contract(asset_metadata_list='list(AssetMetadata)')
    def save_asset_metadata_list(self, asset_metadata_list, user_id, import_only):
        """
        Saves a list of asset metadata for a particular course's asset.
@@ -741,7 +723,6 @@ class ModuleStoreAssetWriteInterface(ModuleStoreAssetBase):
        """
        raise NotImplementedError()

-    @contract(asset_key='AssetKey', attr=str)
    def set_asset_metadata_attr(self, asset_key, attr, value, user_id):
        """
        Add/set the given attr on the asset at the given location. Value can be any type which pymongo accepts.
@@ -758,7 +739,6 @@ class ModuleStoreAssetWriteInterface(ModuleStoreAssetBase):
        """
        return self.set_asset_metadata_attrs(asset_key, {attr: value}, user_id)

-    @contract(source_course_key='CourseKey', dest_course_key='CourseKey')
    def copy_all_asset_metadata(self, source_course_key, dest_course_key, user_id):
        """
        Copy all the course assets from source_course_key to dest_course_key.
@@ -832,7 +812,6 @@ class ModuleStoreRead(ModuleStoreAssetBase, metaclass=ABCMeta):
        """
        pass  # lint-amnesty, pylint: disable=unnecessary-pass

-    @contract(block='XBlock | BlockData | dict', qualifiers=dict)
    def _block_matches(self, block, qualifiers):
        """
        Return True or False depending on whether the field value (block contents)
--- a/common/lib/xmodule/xmodule/modulestore/mixed.py
+++ b/common/lib/xmodule/xmodule/modulestore/mixed.py
@@ -11,9 +11,8 @@ import itertools
 import logging
 from contextlib import contextmanager

-from contracts import contract, new_contract
 from opaque_keys import InvalidKeyError
-from opaque_keys.edx.keys import AssetKey, CourseKey
+from opaque_keys.edx.keys import CourseKey
 from opaque_keys.edx.locator import LibraryLocator

 from xmodule.assetstore import AssetMetadata
@@ -23,12 +22,6 @@ from .draft_and_published import ModuleStoreDraftAndPublished
 from .exceptions import DuplicateCourseError, ItemNotFoundError
 from .split_migrator import SplitMigrator

-new_contract('CourseKey', CourseKey)
-new_contract('AssetKey', AssetKey)
-new_contract('AssetMetadata', AssetMetadata)
-new_contract('LibraryLocator', LibraryLocator)
-new_contract('long', int)
-
 log = logging.getLogger(__name__)


@@ -415,7 +408,6 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
            return None

    @strip_key
-    @contract(library_key='LibraryLocator')
    def get_library(self, library_key, depth=0, **kwargs):
        """
        returns the library block associated with the given key. If no such library exists,
@@ -456,7 +448,6 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
        store = self._get_modulestore_for_courselike(course_key)
        return store.delete_course(course_key, user_id)

-    @contract(asset_metadata='AssetMetadata', user_id='int|long', import_only=bool)
    def save_asset_metadata(self, asset_metadata, user_id, import_only=False):
        """
        Saves the asset metadata for a particular course's asset.
@@ -472,7 +463,6 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
        store = self._get_modulestore_for_courselike(asset_metadata.asset_id.course_key)
        return store.save_asset_metadata(asset_metadata, user_id, import_only)

-    @contract(asset_metadata_list='list(AssetMetadata)', user_id='int|long', import_only=bool)
    def save_asset_metadata_list(self, asset_metadata_list, user_id, import_only=False):
        """
        Saves the asset metadata for each asset in a list of asset metadata.
@@ -492,7 +482,6 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
        return store.save_asset_metadata_list(asset_metadata_list, user_id, import_only)

    @strip_key
-    @contract(asset_key='AssetKey')
    def find_asset_metadata(self, asset_key, **kwargs):
        """
        Find the metadata for a particular course asset.
@@ -507,7 +496,6 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
        return store.find_asset_metadata(asset_key, **kwargs)

    @strip_key
-    @contract(course_key='CourseKey', asset_type='None | str', start=int, maxresults=int, sort='tuple|None')
    def get_all_asset_metadata(self, course_key, asset_type, start=0, maxresults=-1, sort=None, **kwargs):
        """
        Returns a list of static assets for a course.
@@ -529,7 +517,6 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
        store = self._get_modulestore_for_courselike(course_key)
        return store.get_all_asset_metadata(course_key, asset_type, start, maxresults, sort, **kwargs)

-    @contract(asset_key='AssetKey', user_id='int|long')
    def delete_asset_metadata(self, asset_key, user_id):
        """
        Deletes a single asset's metadata.
@@ -544,7 +531,6 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
        store = self._get_modulestore_for_courselike(asset_key.course_key)
        return store.delete_asset_metadata(asset_key, user_id)

-    @contract(source_course_key='CourseKey', dest_course_key='CourseKey', user_id='int|long')
    def copy_all_asset_metadata(self, source_course_key, dest_course_key, user_id):
        """
        Copy all the course assets from source_course_key to dest_course_key.
@@ -570,7 +556,6 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
            # Courses in the same modulestore can be handled by the modulestore itself.
            source_store.copy_all_asset_metadata(source_course_key, dest_course_key, user_id)

-    @contract(asset_key='AssetKey', attr=str, user_id='int|long')
    def set_asset_metadata_attr(self, asset_key, attr, value, user_id):
        """
        Add/set the given attr on the asset at the given location. Value can be any type which pymongo accepts.
@@ -588,7 +573,6 @@ class MixedModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase):
        store = self._get_modulestore_for_courselike(asset_key.course_key)
        return store.set_asset_metadata_attrs(asset_key, {attr: value}, user_id)

-    @contract(asset_key='AssetKey', attr_dict=dict, user_id='int|long')
    def set_asset_metadata_attrs(self, asset_key, attr_dict, user_id):  # lint-amnesty, pylint: disable=arguments-differ
        """
        Add/set the given dict of attrs on the asset at the given location. Value can be any type which pymongo accepts.
--- a/common/lib/xmodule/xmodule/modulestore/mongo/base.py
+++ b/common/lib/xmodule/xmodule/modulestore/mongo/base.py
@@ -23,10 +23,9 @@ from uuid import uuid4

 import pymongo
 from bson.son import SON
-from contracts import contract, new_contract
 from fs.osfs import OSFS
 from mongodb_proxy import autoretry_read
-from opaque_keys.edx.keys import AssetKey, CourseKey, UsageKey
+from opaque_keys.edx.keys import CourseKey, UsageKey
 from opaque_keys.edx.locator import BlockUsageLocator, CourseLocator, LibraryLocator
 from path import Path as path
 from pytz import UTC
@@ -54,12 +53,6 @@ from xmodule.services import SettingsService

 log = logging.getLogger(__name__)

-new_contract('CourseKey', CourseKey)
-new_contract('AssetKey', AssetKey)
-new_contract('AssetMetadata', AssetMetadata)
-new_contract('long', int)
-new_contract('BlockUsageLocator', BlockUsageLocator)
-
 # sort order that returns DRAFT items first
 SORT_REVISION_FAVOR_DRAFT = ('_id.revision', pymongo.DESCENDING)

@@ -422,9 +415,6 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
        return []


-new_contract('CachingDescriptorSystem', CachingDescriptorSystem)
-
-
 # The only thing using this w/ wildcards is contentstore.mongo for asset retrieval
 def location_to_query(location, wildcard=True, tag='i4x'):
    """
@@ -512,15 +502,12 @@ class ParentLocationCache(dict):
    Dict-based object augmented with a more cache-like interface, for internal use.
    """

-    @contract(key=str)
    def has(self, key):
        return key in self

-    @contract(key=str, value="BlockUsageLocator | None")
    def set(self, key, value):
        self[key] = value

-    @contract(value="BlockUsageLocator")
    def delete_by_value(self, value):
        keys_to_delete = [k for k, v in self.items() if v == value]
        for key in keys_to_delete:
@@ -874,12 +861,6 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo

        return data

-    @contract(
-        course_key=CourseKey,
-        item=dict,
-        apply_cached_metadata=bool,
-        using_descriptor_system="None|CachingDescriptorSystem"
-    )
    def _load_item(self, course_key, item, data_cache,
                   apply_cached_metadata=True, using_descriptor_system=None, for_parent=None):
        """
@@ -1831,7 +1812,6 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
        """
        return f'assets.{asset_type}'

-    @contract(asset_metadata_list='list(AssetMetadata)', user_id='int|long')
    def _save_asset_metadata_list(self, asset_metadata_list, user_id, import_only):
        """
        Internal; saves the info for a particular course's asset.
@@ -1857,7 +1837,6 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
        )
        return True

-    @contract(asset_metadata='AssetMetadata', user_id='int|long')
    def save_asset_metadata(self, asset_metadata, user_id, import_only=False):
        """
        Saves the info for a particular course's asset.
@@ -1872,7 +1851,6 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
        """
        return self._save_asset_metadata_list([asset_metadata, ], user_id, import_only)

-    @contract(asset_metadata_list='list(AssetMetadata)', user_id='int|long')
    def save_asset_metadata_list(self, asset_metadata_list, user_id, import_only=False):
        """
        Saves the asset metadata for each asset in a list of asset metadata.
@@ -1888,7 +1866,6 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
        """
        return self._save_asset_metadata_list(asset_metadata_list, user_id, import_only)

-    @contract(source_course_key='CourseKey', dest_course_key='CourseKey', user_id='int|long')
    def copy_all_asset_metadata(self, source_course_key, dest_course_key, user_id):
        """
        Copy all the course assets from source_course_key to dest_course_key.
@@ -1905,7 +1882,6 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
        # Update the document.
        self.asset_collection.insert_one(dest_assets)

-    @contract(asset_key='AssetKey', attr_dict=dict, user_id='int|long')
    def set_asset_metadata_attrs(self, asset_key, attr_dict, user_id):  # lint-amnesty, pylint: disable=arguments-differ
        """
        Add/set the given dict of attrs on the asset at the given location. Value can be any type which pymongo accepts.
@@ -1936,7 +1912,6 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
            {"$set": {self._make_mongo_asset_key(asset_key.asset_type): all_assets}}
        )

-    @contract(asset_key='AssetKey', user_id='int|long')
    def delete_asset_metadata(self, asset_key, user_id):
        """
        Internal; deletes a single asset's metadata.
@@ -1961,7 +1936,6 @@ class MongoModuleStore(ModuleStoreDraftAndPublished, ModuleStoreWriteBase, Mongo
        )
        return 1

-    @contract(course_key='CourseKey', user_id='int|long')
    def delete_all_asset_metadata(self, course_key, user_id):  # lint-amnesty, pylint: disable=unused-argument
        """
        Delete all of the assets which use this course_key as an identifier.
--- a/common/lib/xmodule/xmodule/modulestore/split_mongo/init.py
+++ b/common/lib/xmodule/xmodule/modulestore/split_mongo/init.py
@@ -5,19 +5,16 @@ General utilities

 from collections import namedtuple

-from contracts import check, contract
 from opaque_keys.edx.locator import BlockUsageLocator


 class BlockKey(namedtuple('BlockKey', 'type id')):  # lint-amnesty, pylint: disable=missing-class-docstring
    __slots__ = ()

-    @contract(type="string[>0]")
    def __new__(cls, type, id):  # lint-amnesty, pylint: disable=redefined-builtin
        return super().__new__(cls, type, id)

    @classmethod
-    @contract(usage_key=BlockUsageLocator)
    def from_usage_key(cls, usage_key):
        return cls(usage_key.block_type, usage_key.block_id)

--- a/common/lib/xmodule/xmodule/modulestore/split_mongo/caching_descriptor_system.py
+++ b/common/lib/xmodule/xmodule/modulestore/split_mongo/caching_descriptor_system.py
@@ -3,11 +3,9 @@
 import logging
 import sys

-from contracts import contract, new_contract
 from fs.osfs import OSFS
 from lazy import lazy
-from opaque_keys.edx.locator import BlockUsageLocator, CourseLocator, DefinitionLocator, LibraryLocator, LocalId
-from xblock.core import XBlock
+from opaque_keys.edx.locator import BlockUsageLocator, DefinitionLocator, LocalId
 from xblock.fields import ScopeIds
 from xblock.runtime import KeyValueStore, KvsFieldData

@@ -15,7 +13,6 @@ from xmodule.error_module import ErrorBlock
 from xmodule.errortracker import exc_info_to_str
 from xmodule.library_tools import LibraryToolsService
 from xmodule.mako_module import MakoDescriptorSystem
-from xmodule.modulestore import BlockData
 from xmodule.modulestore.edit_info import EditInfoRuntimeMixin
 from xmodule.modulestore.exceptions import ItemNotFoundError
 from xmodule.modulestore.inheritance import InheritanceMixin, inheriting_field_data
@@ -27,14 +24,6 @@ from xmodule.x_module import XModuleMixin

 log = logging.getLogger(__name__)

-new_contract('BlockUsageLocator', BlockUsageLocator)
-new_contract('CourseLocator', CourseLocator)
-new_contract('LibraryLocator', LibraryLocator)
-new_contract('BlockKey', BlockKey)
-new_contract('BlockData', BlockData)
-new_contract('CourseEnvelope', CourseEnvelope)
-new_contract('XBlock', XBlock)
-

 class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # lint-amnesty, pylint: disable=abstract-method
    """
@@ -43,7 +32,6 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li

    Computes the settings (nee 'metadata') inheritance upon creation.
    """
-    @contract(course_entry=CourseEnvelope)
    def __init__(self, modulestore, course_entry, default_class, module_data, lazy, **kwargs):  # lint-amnesty, pylint: disable=redefined-outer-name
        """
        Computes the settings inheritance and sets up the cache.
@@ -87,7 +75,6 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
        self._services['library_tools'] = LibraryToolsService(modulestore, user_id=None)

    @lazy
-    @contract(returns="dict(BlockKey: BlockKey)")
    def _parent_map(self):  # lint-amnesty, pylint: disable=missing-function-docstring
        parent_map = {}
        for block_key, block in self.course_entry.structure['blocks'].items():
@@ -95,7 +82,6 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
                parent_map[child] = block_key
        return parent_map

-    @contract(usage_key="BlockUsageLocator | BlockKey", course_entry_override="CourseEnvelope | None")
    def _load_item(self, usage_key, course_entry_override=None, **kwargs):
        """
        Instantiate the xblock fetching it either from the cache or from the structure
@@ -143,7 +129,6 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
        self.modulestore.cache_block(course_key, version_guid, block_key, block)
        return block

-    @contract(block_key=BlockKey, course_key="CourseLocator | LibraryLocator")
    def get_module_data(self, block_key, course_key):
        """
        Get block from module_data adding it to module_data if it's not already there but is in the structure
@@ -172,7 +157,6 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
    # low; thus, the course_entry is most likely correct. If the thread is looking at > 1 named container
    # pointing to the same structure, the access is likely to be chunky enough that the last known container
    # is the intended one when not given a course_entry_override; thus, the caching of the last branch/course id.
-    @contract(block_key="BlockKey | None")
    def xblock_from_json(self, class_, course_key, block_key, block_data, course_entry_override=None, **kwargs):
        """
        Load and return block info.
@@ -299,7 +283,6 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
        """
        return xblock._edited_on  # lint-amnesty, pylint: disable=protected-access

-    @contract(xblock='XBlock')
    def get_subtree_edited_by(self, xblock):
        """
        See :class: cms.lib.xblock.runtime.EditInfoRuntimeMixin
@@ -315,7 +298,6 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li

        return xblock._subtree_edited_by

-    @contract(xblock='XBlock')
    def get_subtree_edited_on(self, xblock):
        """
        See :class: cms.lib.xblock.runtime.EditInfoRuntimeMixin
@@ -349,7 +331,6 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li

        return getattr(xblock, '_published_on', None)

-    @contract(block_data='BlockData')
    def _compute_subtree_edited_internal(self, block_data, course_key):
        """
        Recurse the subtree finding the max edited_on date and its corresponding edited_by. Cache it.
--- a/common/lib/xmodule/xmodule/modulestore/split_mongo/mongo_connection.py
+++ b/common/lib/xmodule/xmodule/modulestore/split_mongo/mongo_connection.py
@@ -14,7 +14,6 @@ from time import time

 import pymongo
 import pytz
-from contracts import check, new_contract
 from mongodb_proxy import autoretry_read
 # Import this just to export it
 from pymongo.errors import DuplicateKeyError  # pylint: disable=unused-import
@@ -29,7 +28,6 @@ try:
 except ImportError:
    DJANGO_AVAILABLE = False

-new_contract('BlockData', BlockData)
 log = logging.getLogger(__name__)


@@ -156,12 +154,6 @@ def structure_from_mongo(structure, course_context=None):
    with TIMER.timer('structure_from_mongo', course_context) as tagger:
        tagger.measure('blocks', len(structure['blocks']))

-        check('seq[2]', structure['root'])
-        check('list(dict)', structure['blocks'])
-        for block in structure['blocks']:
-            if 'children' in block['fields']:
-                check('list(list[2])', block['fields']['children'])
-
        structure['root'] = BlockKey(*structure['root'])
        new_blocks = {}
        for block in structure['blocks']:
@@ -184,12 +176,6 @@ def structure_to_mongo(structure, course_context=None):
    with TIMER.timer('structure_to_mongo', course_context) as tagger:
        tagger.measure('blocks', len(structure['blocks']))

-        check('BlockKey', structure['root'])
-        check('dict(BlockKey: BlockData)', structure['blocks'])
-        for block in structure['blocks'].values():
-            if 'children' in block.fields:
-                check('list(BlockKey)', block.fields['children'])
-
        new_structure = dict(structure)
        new_structure['blocks'] = []

--- a/common/lib/xmodule/xmodule/modulestore/split_mongo/split.py
+++ b/common/lib/xmodule/xmodule/modulestore/split_mongo/split.py
@@ -64,7 +64,6 @@ from importlib import import_module

 from bson.objectid import ObjectId
 from ccx_keys.locator import CCXBlockUsageLocator, CCXLocator
-from contracts import contract, new_contract
 from mongodb_proxy import autoretry_read
 from opaque_keys.edx.keys import CourseKey
 from opaque_keys.edx.locator import (
@@ -134,11 +133,6 @@ log = logging.getLogger(__name__)
 EXCLUDE_ALL = '*'


-new_contract('BlockUsageLocator', BlockUsageLocator)
-new_contract('BlockKey', BlockKey)
-new_contract('XBlock', XBlock)
-
-
 class SplitBulkWriteRecord(BulkOpsRecord):  # lint-amnesty, pylint: disable=missing-class-docstring
    def __init__(self):
        super().__init__()
@@ -815,7 +809,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
            system.module_data.update(new_module_data)
            return system.module_data

-    @contract(course_entry=CourseEnvelope, block_keys="list(BlockKey)", depth="int | None")
    def _load_items(self, course_entry, block_keys, depth=0, **kwargs):
        """
        Load & cache the given blocks from the course. May return the blocks in any order.
@@ -1224,7 +1217,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):

        return self._get_block_from_structure(course_structure, BlockKey.from_usage_key(usage_key)) is not None

-    @contract(returns='XBlock')
    def get_item(self, usage_key, depth=0, **kwargs):  # lint-amnesty, pylint: disable=arguments-differ
        """
        depth (int): An argument that some module stores may use to prefetch
@@ -1724,7 +1716,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
                return potential_key
            serial += 1

-    @contract(returns='XBlock')
    def create_item(self, user_id, course_key, block_type, block_id=None, definition_locator=None, fields=None,  # lint-amnesty, pylint: disable=arguments-differ
                    asides=None, force=False, **kwargs):
        """
@@ -2491,7 +2482,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
            self.update_structure(destination_course, destination_structure)
            self._update_head(destination_course, index_entry, destination_course.branch, destination_structure['_id'])

-    @contract(source_keys="list(BlockUsageLocator)", dest_usage=BlockUsageLocator)
    def copy_from_template(self, source_keys, dest_usage, user_id, head_validation=True):
        """
        Flexible mechanism for inheriting content from an external course/library/etc.
@@ -2723,7 +2713,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):

            return result

-    @contract(root_block_key=BlockKey, blocks='dict(BlockKey: BlockData)')
    def _remove_subtree(self, root_block_key, blocks):
        """
        Remove the subtree rooted at root_block_key
@@ -2772,7 +2761,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):

        self._emit_course_deleted_signal(course_key)

-    @contract(block_map="dict(BlockKey: dict)", block_key=BlockKey)
    def inherit_settings(
        self, block_map, block_key, inherited_settings_map, inheriting_settings=None, inherited_from=None
    ):
@@ -2927,7 +2915,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
        """
        return self.save_asset_metadata_list([asset_metadata, ], user_id, import_only)

-    @contract(asset_key='AssetKey', attr_dict=dict)
    def set_asset_metadata_attrs(self, asset_key, attr_dict, user_id):  # lint-amnesty, pylint: disable=arguments-differ
        """
        Add/set the given dict of attrs on the asset at the given location. Value can be any type which pymongo accepts.
@@ -2958,7 +2945,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):

        self._update_course_assets(user_id, asset_key, _internal_method)

-    @contract(asset_key='AssetKey')
    def delete_asset_metadata(self, asset_key, user_id):
        """
        Internal; deletes a single asset's metadata.
@@ -2985,7 +2971,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
        except ItemNotFoundError:
            return 0

-    @contract(source_course_key='CourseKey', dest_course_key='CourseKey')
    def copy_all_asset_metadata(self, source_course_key, dest_course_key, user_id):
        """
        Copy all the course assets from source_course_key to dest_course_key.
@@ -3037,7 +3022,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
        and converting them.
        :param jsonfields: the serialized copy of the xblock's fields
        """
-        @contract(block_key="BlockUsageLocator | seq[2]")
        def robust_usage_key(block_key):
            """
            create a course_key relative usage key for the block_key. If the block_key is in blocks,
@@ -3220,7 +3204,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
            'schema_version': self.SCHEMA_VERSION,
        }

-    @contract(block_key=BlockKey)
    def _get_parents_from_structure(self, block_key, structure):
        """
        Given a structure, find block_key's parent in that structure. Note returns
@@ -3247,12 +3230,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
        destination_parent.fields['children'] = destination_reordered
        return orphans

-    @contract(
-        block_key=BlockKey,
-        source_blocks="dict(BlockKey: *)",
-        destination_blocks="dict(BlockKey: *)",
-        blacklist="list(BlockKey) | str",
-    )
    def _copy_subdag(self, user_id, destination_version, block_key, source_blocks, destination_blocks, blacklist):
        """
        Update destination_blocks for the sub-dag rooted at block_key to be like the one in
@@ -3321,7 +3298,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
        destination_blocks[block_key] = destination_block
        return orphans

-    @contract(blacklist='list(BlockKey) | str')
    def _filter_blacklist(self, fields, blacklist):
        """
        Filter out blacklist from the children field in fields. Will construct a new list for children;
@@ -3333,7 +3309,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
            fields['children'] = [child for child in fields.get('children', []) if BlockKey(*child) not in blacklist]
        return fields

-    @contract(orphan=BlockKey)
    def _delete_if_true_orphan(self, orphan, structure):
        """
        Delete the orphan and any of its descendants which no longer have parents.
@@ -3343,7 +3318,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
            for child in orphan_data.fields.get('children', []):
                self._delete_if_true_orphan(BlockKey(*child), structure)

-    @contract(returns=BlockData)
    def _new_block(self, user_id, category, block_fields, definition_id, new_id, raw=False,
                   asides=None, block_defaults=None):
        """
@@ -3375,7 +3349,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
            document['defaults'] = block_defaults
        return BlockData(**document)

-    @contract(block_key=BlockKey, returns='BlockData | None')
    def _get_block_from_structure(self, structure, block_key):
        """
        Encodes the block key before retrieving it from the structure to ensure it can
@@ -3383,7 +3356,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
        """
        return structure['blocks'].get(block_key)

-    @contract(block_key=BlockKey)
    def _get_asides_to_update_from_structure(self, structure, block_key, asides):
        """
        Get list of aside fields that should be updated/inserted
@@ -3415,7 +3387,6 @@ class SplitMongoModuleStore(SplitBulkWriteMixin, ModuleStoreWriteBase):
        else:
            return block.asides, False

-    @contract(block_key=BlockKey, content=BlockData)
    def _update_block_in_structure(self, structure, block_key, content):
        """
        Encodes the block key before accessing it in the structure to ensure it can
--- a/common/lib/xmodule/xmodule/modulestore/split_mongo/split_draft.py
+++ b/common/lib/xmodule/xmodule/modulestore/split_mongo/split_draft.py
@@ -3,7 +3,6 @@ Module for the dual-branch fall-back Draft->Published Versioning ModuleStore
 """


-from contracts import contract
 from opaque_keys.edx.locator import CourseLocator, LibraryLocator, LibraryUsageLocator

 from xmodule.exceptions import InvalidVersionError
@@ -612,7 +611,6 @@ class DraftVersioningModuleStore(SplitMongoModuleStore, ModuleStoreDraftAndPubli
            xblock._published_by = published_block.edit_info.edited_by
            xblock._published_on = published_block.edit_info.edited_on

-    @contract(asset_key='AssetKey')
    def find_asset_metadata(self, asset_key, **kwargs):
        return super().find_asset_metadata(
            self._map_revision_to_branch(asset_key), **kwargs
--- a/common/lib/xmodule/xmodule/modulestore/split_mongo/split_mongo_kvs.py
+++ b/common/lib/xmodule/xmodule/modulestore/split_mongo/split_mongo_kvs.py
@@ -3,8 +3,6 @@
 import copy
 from collections import namedtuple

-from contracts import contract, new_contract
-from opaque_keys.edx.locator import BlockUsageLocator
 from xblock.core import XBlockAside
 from xblock.exceptions import InvalidScopeError
 from xblock.fields import Scope
@@ -15,7 +13,6 @@ from .definition_lazy_loader import DefinitionLazyLoader

 # id is a BlockUsageLocator, def_id is the definition's guid
 SplitMongoKVSid = namedtuple('SplitMongoKVSid', 'id, def_id')
-new_contract('BlockUsageLocator', BlockUsageLocator)


 class SplitMongoKVS(InheritanceKeyValueStore):
@@ -26,7 +23,6 @@ class SplitMongoKVS(InheritanceKeyValueStore):

    VALID_SCOPES = (Scope.parent, Scope.children, Scope.settings, Scope.content)

-    @contract(parent="BlockUsageLocator | None")
    def __init__(self, definition, initial_values, default_values, parent, aside_fields=None, field_decorator=None):
        """

--- a/common/lib/xmodule/xmodule/modulestore/tests/test_split_modulestore.py
+++ b/common/lib/xmodule/xmodule/modulestore/tests/test_split_modulestore.py
@@ -14,7 +14,6 @@ from unittest.mock import patch
 import pytest
 import ddt
 from ccx_keys.locator import CCXBlockUsageLocator
-from contracts import contract
 from django.core.cache import InvalidCacheBackendError, caches
 from opaque_keys.edx.locator import BlockUsageLocator, CourseKey, CourseLocator, LocalId, VersionTree
 from path import Path as path
@@ -2125,7 +2124,6 @@ class TestPublish(SplitModuleTest):
        ]
        self._check_course(source_course, dest_course, expected, [BlockKey("chapter", "chapter2"), BlockKey("problem", "problem3_2")])  # lint-amnesty, pylint: disable=line-too-long

-    @contract(expected_blocks="list(BlockKey)", unexpected_blocks="list(BlockKey)")
    def _check_course(self, source_course_loc, dest_course_loc, expected_blocks, unexpected_blocks):
        """
        Check that the course has the expected blocks and does not have the unexpected blocks
@@ -2164,11 +2162,6 @@ class TestPublish(SplitModuleTest):
            actual = {key: BlockKey.from_usage_key(val) for (key, val) in actual}
        assert expected == actual

-    @contract(
-        source_children="list(BlockUsageLocator)",
-        dest_children="list(BlockUsageLocator)",
-        unexpected="list(BlockKey)"
-    )
    def _compare_children(self, source_children, dest_children, unexpected):
        """
        Ensure dest_children == source_children minus unexpected
--- a/common/lib/xmodule/xmodule/x_module.py
+++ b/common/lib/xmodule/xmodule/x_module.py
@@ -8,7 +8,6 @@ from collections import namedtuple
 from functools import partial

 import yaml
-from contracts import contract, new_contract
 from django.utils.encoding import python_2_unicode_compatible
 from lazy import lazy
 from lxml import etree
@@ -1618,9 +1617,6 @@ class DescriptorSystem(MetricsMixin, ConfigurableFragmentWrapper, Runtime):
        return service


-new_contract('DescriptorSystem', DescriptorSystem)
-
-
 class XMLParsingSystem(DescriptorSystem):  # lint-amnesty, pylint: disable=abstract-method, missing-class-docstring
    def __init__(self, process_xml, **kwargs):
        """
@@ -1750,7 +1746,6 @@ class ModuleSystem(MetricsMixin, ConfigurableFragmentWrapper, Runtime):
    and user, or other environment-specific info.
    """

-    @contract(descriptor_runtime='DescriptorSystem')
    def __init__(
            self, static_url, track_function, get_module, render_template,
            replace_urls, descriptor_runtime, user=None, filestore=None,
--- a/docs/guides/conf.py
+++ b/docs/guides/conf.py
@@ -214,7 +214,6 @@ intersphinx_mapping = {
 # Mock out these external modules during code import to avoid errors
 autodoc_mock_imports = [
    'MySQLdb',
-    'contracts',
    'django_mysql',
    'pymongo',
 ]
--- a/lms/djangoapps/courseware/model_data.py
+++ b/lms/djangoapps/courseware/model_data.py
@@ -27,7 +27,6 @@ import logging
 from abc import ABCMeta, abstractmethod
 from collections import defaultdict, namedtuple

-from contracts import contract, new_contract
 from django.db import DatabaseError, IntegrityError, transaction
 from opaque_keys.edx.asides import AsideUsageKeyV1, AsideUsageKeyV2
 from opaque_keys.edx.block_types import BlockTypeKeyV1
@@ -149,10 +148,6 @@ class DjangoKeyValueStore(KeyValueStore):
            raise InvalidScopeError(key, self._allowed_scopes)


-new_contract("DjangoKeyValueStore", DjangoKeyValueStore)
-new_contract("DjangoKeyValueStore_Key", DjangoKeyValueStore.Key)
-
-
 class DjangoOrmFieldCache(metaclass=ABCMeta):
    """
    Baseclass for Scope-specific field cache objects that are based on
@@ -175,7 +170,6 @@ class DjangoOrmFieldCache(metaclass=ABCMeta):
        for field_object in self._read_objects(fields, xblocks, aside_types):
            self._cache[self._cache_key_for_field_object(field_object)] = field_object

-    @contract(kvs_key=DjangoKeyValueStore.Key)
    def get(self, kvs_key):
        """
        Return the django model object specified by `kvs_key` from
@@ -194,7 +188,6 @@ class DjangoOrmFieldCache(metaclass=ABCMeta):

        return json.loads(field_object.value)

-    @contract(kvs_key=DjangoKeyValueStore.Key)
    def set(self, kvs_key, value):
        """
        Set the specified `kvs_key` to the field value `value`.
@@ -205,7 +198,6 @@ class DjangoOrmFieldCache(metaclass=ABCMeta):
        """
        self.set_many({kvs_key: value})

-    @contract(kv_dict="dict(DjangoKeyValueStore_Key: *)")
    def set_many(self, kv_dict):
        """
        Set the specified fields to the supplied values.
@@ -241,7 +233,6 @@ class DjangoOrmFieldCache(metaclass=ABCMeta):
            finally:
                saved_fields.append(kvs_key.field_name)

-    @contract(kvs_key=DjangoKeyValueStore.Key)
    def delete(self, kvs_key):
        """
        Delete the value specified by `kvs_key`.
@@ -260,7 +251,6 @@ class DjangoOrmFieldCache(metaclass=ABCMeta):
        field_object.delete()
        del self._cache[cache_key]

-    @contract(kvs_key=DjangoKeyValueStore.Key, returns=bool)
    def has(self, kvs_key):
        """
        Return whether the specified `kvs_key` is set.
@@ -272,7 +262,6 @@ class DjangoOrmFieldCache(metaclass=ABCMeta):
        """
        return self._cache_key_for_kvs_key(kvs_key) in self._cache

-    @contract(kvs_key=DjangoKeyValueStore.Key, returns="datetime|None")
    def last_modified(self, kvs_key):
        """
        Return when the supplied field was changed.
@@ -368,7 +357,6 @@ class UserStateCache:
        for user_state in block_field_state:
            self._cache[user_state.block_key] = user_state.state

-    @contract(kvs_key=DjangoKeyValueStore.Key)
    def set(self, kvs_key, value):
        """
        Set the specified `kvs_key` to the field value `value`.
@@ -379,7 +367,6 @@ class UserStateCache:
        """
        self.set_many({kvs_key: value})

-    @contract(kvs_key=DjangoKeyValueStore.Key, returns="datetime|None")
    def last_modified(self, kvs_key):
        """
        Return when the supplied field was changed.
@@ -398,7 +385,6 @@ class UserStateCache:
        except self._client.DoesNotExist:
            return None

-    @contract(kv_dict="dict(DjangoKeyValueStore_Key: *)")
    def set_many(self, kv_dict):
        """
        Set the specified fields to the supplied values.
@@ -424,7 +410,6 @@ class UserStateCache:
        finally:
            self._cache.update(pending_updates)

-    @contract(kvs_key=DjangoKeyValueStore.Key)
    def get(self, kvs_key):
        """
        Return the django model object specified by `kvs_key` from
@@ -441,7 +426,6 @@ class UserStateCache:

        return self._cache[cache_key][kvs_key.field_name]

-    @contract(kvs_key=DjangoKeyValueStore.Key)
    def delete(self, kvs_key):
        """
        Delete the value specified by `kvs_key`.
@@ -463,7 +447,6 @@ class UserStateCache:
        self._client.delete(self.user.username, cache_key, fields=[kvs_key.field_name])
        del field_state[kvs_key.field_name]

-    @contract(kvs_key=DjangoKeyValueStore.Key, returns=bool)
    def has(self, kvs_key):
        """
        Return whether the specified `kvs_key` is set.
@@ -803,7 +786,6 @@ class FieldDataCache:
                scope_map[field.scope].add(field)
        return scope_map

-    @contract(key=DjangoKeyValueStore.Key)
    def get(self, key):
        """
        Load the field value specified by `key`.
@@ -825,7 +807,6 @@ class FieldDataCache:

        return self.cache[key.scope].get(key)

-    @contract(kv_dict="dict(DjangoKeyValueStore_Key: *)")
    def set_many(self, kv_dict):
        """
        Set all of the fields specified by the keys of `kv_dict` to the values
@@ -862,7 +843,6 @@ class FieldDataCache:
                log.exception('Error saving fields %r', [key.field_name for key in set_many_data])
                raise KeyValueMultiSaveError(saved_fields + exc.saved_field_names)  # lint-amnesty, pylint: disable=raise-missing-from

-    @contract(key=DjangoKeyValueStore.Key)
    def delete(self, key):
        """
        Delete the value specified by `key`.
@@ -885,7 +865,6 @@ class FieldDataCache:

        self.cache[key.scope].delete(key)

-    @contract(key=DjangoKeyValueStore.Key, returns=bool)
    def has(self, key):
        """
        Return whether the specified `key` is set.
@@ -906,7 +885,6 @@ class FieldDataCache:

        return self.cache[key.scope].has(key)

-    @contract(key=DjangoKeyValueStore.Key, returns="datetime|None")
    def last_modified(self, key):
        """
        Return when the supplied field was changed.
@@ -989,7 +967,6 @@ class ScoresClient:
        return client


-# @contract(user_id=int, usage_key=UsageKey, score="number|None", max_score="number|None")
 def set_score(user_id, usage_key, score, max_score):
    """
    Set the score and max_score for the specified user and xblock usage.
--- a/lms/wsgi.py
+++ b/lms/wsgi.py
@@ -12,10 +12,6 @@ It exposes a module-level variable named ``application``. Django's
 from safe_lxml import defuse_xml_libs
 defuse_xml_libs()

-# Disable PyContract contract checking when running as a webserver
-import contracts  # lint-amnesty, pylint: disable=wrong-import-order, wrong-import-position
-contracts.disable_all()
-
 import os  # lint-amnesty, pylint: disable=wrong-import-order, wrong-import-position
 os.environ.setdefault("DJANGO_SETTINGS_MODULE", "lms.envs.aws")

--- a/manage.py
+++ b/manage.py
@@ -25,8 +25,6 @@ import os
 import sys
 from argparse import ArgumentParser

-import contracts
-

 def parse_args():
    """Parse edx specific arguments to manage.py"""
@@ -49,11 +47,6 @@ def parse_args():
        choices=['lms', 'lms-xml', 'lms-preview'],
        default='lms',
        help='Which service variant to run, when using the production environment')
-    lms.add_argument(
-        '--contracts',
-        action='store_true',
-        default=False,
-        help='Turn on pycontracts for local development')
    lms.set_defaults(
        help_string=lms.format_help(),
        settings_base='lms/envs',
@@ -72,11 +65,6 @@ def parse_args():
        help="Which django settings module to use under cms.envs. If not provided, the DJANGO_SETTINGS_MODULE "
             "environment variable will be used if it is set, otherwise it will default to cms.envs.devstack_docker")
    cms.add_argument('-h', '--help', action='store_true', help='show this help message and exit')
-    cms.add_argument(
-        '--contracts',
-        action='store_true',
-        default=False,
-        help='Turn on pycontracts for local development')
    cms.set_defaults(
        help_string=cms.format_help(),
        settings_base='cms/envs',
@@ -106,11 +94,6 @@ if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", edx_args.default_settings)
    os.environ.setdefault("SERVICE_VARIANT", edx_args.service_variant)

-    enable_contracts = os.environ.get('ENABLE_CONTRACTS', False)
-    # can override with '--contracts' argument
-    if not enable_contracts and not edx_args.contracts:
-        contracts.disable_all()
-
    if edx_args.help:
        print("Django:")
        # This will trigger django-admin.py to print out its help
--- a/openedx/core/djangoapps/django_comment_common/tests.py
+++ b/openedx/core/djangoapps/django_comment_common/tests.py
@@ -2,7 +2,6 @@


 import pytest
-from contracts import new_contract
 from django.test import TestCase
 from opaque_keys.edx.locator import CourseLocator

@@ -14,8 +13,6 @@ from xmodule.modulestore.django import modulestore
 from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory

-new_contract('basestring', str)
-

 class RoleAssignmentTest(TestCase):
    """
--- a/openedx/core/djangoapps/django_comment_common/utils.py
+++ b/openedx/core/djangoapps/django_comment_common/utils.py
@@ -2,8 +2,6 @@
 """
 Common comment client utility functions.
 """
-from contracts import new_contract
-
 from openedx.core.djangoapps.django_comment_common.models import (
    FORUM_ROLE_ADMINISTRATOR,
    FORUM_ROLE_COMMUNITY_TA,
@@ -13,8 +11,6 @@ from openedx.core.djangoapps.django_comment_common.models import (
    Role
 )

-new_contract('basestring', str)
-

 class ThreadContext:
    """ An enumeration that represents the context of a thread. Used primarily by the comments service. """
--- a/openedx/core/lib/xblock_utils/init.py
+++ b/openedx/core/lib/xblock_utils/init.py
@@ -12,7 +12,6 @@ import uuid

 import markupsafe
 import webpack_loader.utils
-from contracts import contract
 from django.conf import settings
 from django.contrib.auth.models import User  # lint-amnesty, pylint: disable=imported-auth-user
 from django.contrib.staticfiles.storage import staticfiles_storage
@@ -309,7 +308,6 @@ def sanitize_html_id(html_id):
    return sanitized_html_id


-@contract(user=User, block=XBlock, view=(str,)[0], frag=Fragment, context="dict|None")
 def add_staff_markup(user, disable_staff_debug_info, block, view, frag, context):  # pylint: disable=unused-argument
    """
    Updates the supplied module with a new get_html function that wraps
--- a/pavelib/paver_tests/test_servers.py
+++ b/pavelib/paver_tests/test_servers.py
@@ -100,7 +100,6 @@ class TestPaverServerTasks(PaverTestCase):
        [{"fast": True}],
        [{"optimized": True}],
        [{"optimized": True, "fast": True}],
-        [{"no-contracts": True}],
    )
    @ddt.unpack
    def test_devstack(self, server_options):
@@ -119,7 +118,7 @@ class TestPaverServerTasks(PaverTestCase):
                settings=expected_settings,
            )
        ]
-        self.verify_server_task("devstack", options, contracts_default=True)
+        self.verify_server_task("devstack", options)

        # Then test with Studio
        options["system"] = "cms"
@@ -129,7 +128,7 @@ class TestPaverServerTasks(PaverTestCase):
                settings=expected_settings,
            )
        ]
-        self.verify_server_task("devstack", options, contracts_default=True)
+        self.verify_server_task("devstack", options)

    @ddt.data(
        [{}],
@@ -193,7 +192,7 @@ class TestPaverServerTasks(PaverTestCase):
               ["echo 'import {system}.envs.{settings}' | python manage.py {system} "
                "--settings={settings} shell --plain --pythonpath=.".format(system=system, settings=settings)]

-    def verify_server_task(self, task_name, options, contracts_default=False):
+    def verify_server_task(self, task_name, options):
        """
        Verify the output of a server task.
        """
@@ -202,7 +201,6 @@ class TestPaverServerTasks(PaverTestCase):
        asset_settings = options.get("asset-settings", None)
        is_optimized = options.get("optimized", False)
        is_fast = options.get("fast", False)
-        no_contracts = options.get("no-contracts", not contracts_default)
        if task_name == "devstack":
            system = options.get("system")
        elif task_name == "studio":
@@ -221,8 +219,6 @@ class TestPaverServerTasks(PaverTestCase):
                args.append("--optimized")
            if is_fast:
                args.append("--fast")
-            if no_contracts:
-                args.append("--no-contracts")
            call_task("pavelib.servers.devstack", args=args)
        else:
            call_task(f"pavelib.servers.{task_name}", options=options)
@@ -257,8 +253,6 @@ class TestPaverServerTasks(PaverTestCase):
            settings=expected_settings,
            port=port,
        )
-        if not no_contracts:
-            expected_run_server_command += " --contracts"
        expected_messages.append(expected_run_server_command)
        assert self.task_messages == expected_messages

--- a/pavelib/servers.py
+++ b/pavelib/servers.py
@@ -25,7 +25,7 @@ ASSET_SETTINGS_HELP = (


 def run_server(
-        system, fast=False, settings=None, asset_settings=None, port=None, contracts=False
+        system, fast=False, settings=None, asset_settings=None, port=None
 ):
    """Start the server for LMS or Studio.

@@ -35,7 +35,6 @@ def run_server(
        settings (str): The Django settings module to use; if not provided, use the default.
        asset_settings (str) The settings to use when generating assets. If not provided, assets are not generated.
        port (str): The port number to run the server on. If not provided, uses the default port for the system.
-        contracts (bool) If true then PyContracts is enabled (defaults to False).
    """
    if system not in ['lms', 'studio']:
        print("System must be either lms or studio", file=sys.stderr)
@@ -58,9 +57,6 @@ def run_server(

    args = [settings, 'runserver', '--traceback', '--pythonpath=.', f'0.0.0.0:{port}']

-    if contracts:
-        args.append("--contracts")
-
    run_process(django_cmd(system, *args))


@@ -127,12 +123,6 @@ def devstack(args):
    parser.add_argument('--optimized', action='store_true', default=False, help="Run with optimized assets")
    parser.add_argument('--settings', type=str, default=DEFAULT_SETTINGS, help="Settings file")
    parser.add_argument('--asset-settings', type=str, default=None, help=ASSET_SETTINGS_HELP)
-    parser.add_argument(
-        '--no-contracts',
-        action='store_true',
-        default=False,
-        help="Disable contracts. By default, they're enabled in devstack."
-    )
    args = parser.parse_args(args)
    settings = args.settings
    asset_settings = args.asset_settings if args.asset_settings else settings
@@ -145,7 +135,6 @@ def devstack(args):
        fast=args.fast,
        settings=settings,
        asset_settings=asset_settings,
-        contracts=not args.no_contracts,
    )


--- a/requirements/edx-sandbox/py38.txt
+++ b/requirements/edx-sandbox/py38.txt
@@ -48,7 +48,7 @@ nltk==3.6.2
    # via
    #   -r requirements/edx-sandbox/py38.in
    #   chem
-numpy==1.20.3
+numpy==1.21.0
    # via
    #   -r requirements/edx-sandbox/py38.in
    #   chem
--- a/requirements/edx/base.in
+++ b/requirements/edx/base.in
@@ -123,7 +123,6 @@ openedx-calc                        # Library supporting mathematical calculatio
 ora2
 piexif                              # Exif image metadata manipulation, used in the profile_images app
 Pillow                              # Image manipulation library; used for course assets, profile images, invoice PDFs, etc.
-PyContracts
 pycountry
 pycryptodomex
 pygments                            # Used to support colors in paver command output
--- a/requirements/edx/base.txt
+++ b/requirements/edx/base.txt
@@ -143,8 +143,6 @@ ddt==1.4.2
    # via
    #   xblock-drag-and-drop-v2
    #   xblock-poll
-decorator==5.0.9
-    # via pycontracts
 defusedxml==0.7.1
    # via
    #   -r requirements/edx/base.in
@@ -390,7 +388,7 @@ edx-analytics-data-api-client==0.17.0
    # via -r requirements/edx/base.in
 edx-api-doc-tools==1.4.0
    # via -r requirements/edx/base.in
-edx-bulk-grades==0.8.11
+edx-bulk-grades==0.8.12
    # via
    #   -r requirements/edx/base.in
    #   staff-graded-xblock
@@ -486,7 +484,7 @@ edx-toggles==4.1.0
    #   edx-event-routing-backends
    #   edxval
    #   ora2
-edx-user-state-client==1.3.1
+edx-user-state-client==1.3.2
    # via -r requirements/edx/base.in
 edx-when==2.0.0
    # via
@@ -494,7 +492,7 @@ edx-when==2.0.0
    #   edx-proctoring
 edxval==2.0.3
    # via -r requirements/edx/base.in
-elasticsearch==7.13.2
+elasticsearch==7.13.1
    # via edx-search
 enmerkar-underscore==2.0.0
    # via -r requirements/edx/base.in
@@ -521,7 +519,6 @@ future==0.18.2
    #   django-ses
    #   edx-celeryutils
    #   edx-enterprise
-    #   pycontracts
    #   pyjwkest
 geoip2==3.0.0
    # via
@@ -595,7 +592,9 @@ libsass==0.10.0
 loremipsum==1.0.5
    # via ora2
 lti-consumer-xblock==2.10.1
-    # via -r requirements/edx/base.in
+    # via
+    #   -c requirements/edx/../constraints.txt
+    #   -r requirements/edx/base.in
 lxml==4.5.0
    # via
    #   -c requirements/edx/../constraints.txt
@@ -651,7 +650,7 @@ mpmath==1.2.1
    # via sympy
 mysqlclient==2.0.3
    # via -r requirements/edx/base.in
-newrelic==6.4.1.158
+newrelic==6.4.2.159
    # via
    #   -r requirements/edx/base.in
    #   edx-django-utils
@@ -661,7 +660,7 @@ nltk==3.6.2
    #   chem
 nodeenv==1.6.0
    # via -r requirements/edx/base.in
-numpy==1.20.3
+numpy==1.21.0
    # via
    #   chem
    #   openedx-calc
@@ -676,7 +675,7 @@ oauthlib==3.0.1
    #   social-auth-core
 openedx-calc==2.0.1
    # via -r requirements/edx/base.in
-ora2==3.6.6
+ora2==3.6.7
    # via -r requirements/edx/base.in
 packaging==20.9
    # via
@@ -713,10 +712,6 @@ psutil==5.8.0
    # via
    #   -r requirements/edx/paver.txt
    #   edx-django-utils
-pycontracts==1.8.12
-    # via
-    #   -r requirements/edx/base.in
-    #   edx-user-state-client
 pycountry==20.7.3
    # via -r requirements/edx/base.in
 pycparser==2.20
@@ -761,7 +756,6 @@ pyparsing==2.4.7
    #   chem
    #   openedx-calc
    #   packaging
-    #   pycontracts
 pysrt==1.1.2
    # via
    #   -r requirements/edx/base.in
@@ -919,7 +913,6 @@ six==1.16.0
    #   isodate
    #   libsass
    #   paver
-    #   pycontracts
    #   pyjwkest
    #   python-dateutil
    #   python-memcached
--- a/requirements/edx/development.txt
+++ b/requirements/edx/development.txt
@@ -195,10 +195,6 @@ ddt==1.4.2
    #   -r requirements/edx/testing.txt
    #   xblock-drag-and-drop-v2
    #   xblock-poll
-decorator==5.0.9
-    # via
-    #   -r requirements/edx/testing.txt
-    #   pycontracts
 defusedxml==0.7.1
    # via
    #   -r requirements/edx/testing.txt
@@ -476,7 +472,7 @@ edx-analytics-data-api-client==0.17.0
    # via -r requirements/edx/testing.txt
 edx-api-doc-tools==1.4.0
    # via -r requirements/edx/testing.txt
-edx-bulk-grades==0.8.11
+edx-bulk-grades==0.8.12
    # via
    #   -r requirements/edx/testing.txt
    #   staff-graded-xblock
@@ -582,7 +578,7 @@ edx-toggles==4.1.0
    #   edx-event-routing-backends
    #   edxval
    #   ora2
-edx-user-state-client==1.3.1
+edx-user-state-client==1.3.2
    # via -r requirements/edx/testing.txt
 edx-when==2.0.0
    # via
@@ -590,7 +586,7 @@ edx-when==2.0.0
    #   edx-proctoring
 edxval==2.0.3
    # via -r requirements/edx/testing.txt
-elasticsearch==7.13.2
+elasticsearch==7.13.1
    # via
    #   -r requirements/edx/testing.txt
    #   edx-search
@@ -612,7 +608,7 @@ execnet==1.9.0
    #   pytest-xdist
 factory-boy==3.2.0
    # via -r requirements/edx/testing.txt
-faker==8.8.1
+faker==8.8.2
    # via
    #   -r requirements/edx/testing.txt
    #   factory-boy
@@ -641,7 +637,6 @@ future==0.18.2
    #   django-ses
    #   edx-celeryutils
    #   edx-enterprise
-    #   pycontracts
    #   pyjwkest
 geoip2==3.0.0
    # via
@@ -776,7 +771,9 @@ loremipsum==1.0.5
    #   -r requirements/edx/testing.txt
    #   ora2
 lti-consumer-xblock==2.10.1
-    # via -r requirements/edx/testing.txt
+    # via
+    #   -c requirements/edx/../constraints.txt
+    #   -r requirements/edx/testing.txt
 lxml==4.5.0
    # via
    #   -c requirements/edx/../constraints.txt
@@ -852,11 +849,11 @@ mpmath==1.2.1
    #   sympy
 mypy-extensions==0.4.3
    # via mypy
-mypy==0.902
+mypy==0.910
    # via -r requirements/edx/development.in
 mysqlclient==2.0.3
    # via -r requirements/edx/testing.txt
-newrelic==6.4.1.158
+newrelic==6.4.2.159
    # via
    #   -r requirements/edx/testing.txt
    #   edx-django-utils
@@ -866,7 +863,7 @@ nltk==3.6.2
    #   chem
 nodeenv==1.6.0
    # via -r requirements/edx/testing.txt
-numpy==1.20.3
+numpy==1.21.0
    # via
    #   -r requirements/edx/testing.txt
    #   chem
@@ -882,7 +879,7 @@ oauthlib==3.0.1
    #   social-auth-core
 openedx-calc==2.0.1
    # via -r requirements/edx/testing.txt
-ora2==3.6.6
+ora2==3.6.7
    # via -r requirements/edx/testing.txt
 packaging==20.9
    # via
@@ -922,7 +919,7 @@ pillow==8.2.0
    #   -r requirements/edx/testing.txt
    #   edx-enterprise
    #   edx-organizations
-pip-tools==6.1.0
+pip-tools==6.2.0
    # via -r requirements/edx/pip-tools.txt
 pluggy==0.13.1
    # via
@@ -947,10 +944,6 @@ py==1.10.0
    #   tox
 pycodestyle==2.7.0
    # via -r requirements/edx/testing.txt
-pycontracts==1.8.12
-    # via
-    #   -r requirements/edx/testing.txt
-    #   edx-user-state-client
 pycountry==20.7.3
    # via -r requirements/edx/testing.txt
 pycparser==2.20
@@ -1025,7 +1018,6 @@ pyparsing==2.4.7
    #   chem
    #   openedx-calc
    #   packaging
-    #   pycontracts
 pyquery==1.4.3
    # via -r requirements/edx/testing.txt
 pyrsistent==0.17.3
@@ -1254,7 +1246,6 @@ six==1.16.0
    #   jsonschema
    #   libsass
    #   paver
-    #   pycontracts
    #   pyjwkest
    #   python-dateutil
    #   python-memcached
@@ -1441,6 +1432,10 @@ webob==1.8.7
    #   -r requirements/edx/testing.txt
    #   xblock
    #   xmodule
+wheel==0.36.2
+    # via
+    #   -r requirements/edx/pip-tools.txt
+    #   pip-tools
 wrapt==1.11.2
    # via
    #   -c requirements/edx/../constraints.txt
--- a/requirements/edx/pip-tools.txt
+++ b/requirements/edx/pip-tools.txt
@@ -10,10 +10,13 @@ click==7.1.2
    #   pip-tools
 pep517==0.10.0
    # via pip-tools
-pip-tools==6.1.0
+pip-tools==6.2.0
    # via -r requirements/edx/pip-tools.in
 toml==0.10.2
    # via pep517
+wheel==0.36.2
+    # via pip-tools

 # The following packages are considered to be unsafe in a requirements file:
 # pip
+# setuptools
--- a/requirements/edx/testing.txt
+++ b/requirements/edx/testing.txt
@@ -188,10 +188,6 @@ ddt==1.4.2
    #   -r requirements/edx/testing.in
    #   xblock-drag-and-drop-v2
    #   xblock-poll
-decorator==5.0.9
-    # via
-    #   -r requirements/edx/base.txt
-    #   pycontracts
 defusedxml==0.7.1
    # via
    #   -r requirements/edx/base.txt
@@ -461,7 +457,7 @@ edx-analytics-data-api-client==0.17.0
    # via -r requirements/edx/base.txt
 edx-api-doc-tools==1.4.0
    # via -r requirements/edx/base.txt
-edx-bulk-grades==0.8.11
+edx-bulk-grades==0.8.12
    # via
    #   -r requirements/edx/base.txt
    #   staff-graded-xblock
@@ -566,7 +562,7 @@ edx-toggles==4.1.0
    #   edx-event-routing-backends
    #   edxval
    #   ora2
-edx-user-state-client==1.3.1
+edx-user-state-client==1.3.2
    # via -r requirements/edx/base.txt
 edx-when==2.0.0
    # via
@@ -574,7 +570,7 @@ edx-when==2.0.0
    #   edx-proctoring
 edxval==2.0.3
    # via -r requirements/edx/base.txt
-elasticsearch==7.13.2
+elasticsearch==7.13.1
    # via
    #   -r requirements/edx/base.txt
    #   edx-search
@@ -594,7 +590,7 @@ execnet==1.9.0
    # via pytest-xdist
 factory-boy==3.2.0
    # via -r requirements/edx/testing.in
-faker==8.8.1
+faker==8.8.2
    # via factory-boy
 filelock==3.0.12
    # via
@@ -620,7 +616,6 @@ future==0.18.2
    #   django-ses
    #   edx-celeryutils
    #   edx-enterprise
-    #   pycontracts
    #   pyjwkest
 geoip2==3.0.0
    # via
@@ -743,7 +738,9 @@ loremipsum==1.0.5
    #   -r requirements/edx/base.txt
    #   ora2
 lti-consumer-xblock==2.10.1
-    # via -r requirements/edx/base.txt
+    # via
+    #   -c requirements/edx/../constraints.txt
+    #   -r requirements/edx/base.txt
 lxml==4.5.0
    # via
    #   -c requirements/edx/../constraints.txt
@@ -814,7 +811,7 @@ mpmath==1.2.1
    #   sympy
 mysqlclient==2.0.3
    # via -r requirements/edx/base.txt
-newrelic==6.4.1.158
+newrelic==6.4.2.159
    # via
    #   -r requirements/edx/base.txt
    #   edx-django-utils
@@ -824,7 +821,7 @@ nltk==3.6.2
    #   chem
 nodeenv==1.6.0
    # via -r requirements/edx/base.txt
-numpy==1.20.3
+numpy==1.21.0
    # via
    #   -r requirements/edx/base.txt
    #   chem
@@ -840,7 +837,7 @@ oauthlib==3.0.1
    #   social-auth-core
 openedx-calc==2.0.1
    # via -r requirements/edx/base.txt
-ora2==3.6.6
+ora2==3.6.7
    # via -r requirements/edx/base.txt
 packaging==20.9
    # via
@@ -898,10 +895,6 @@ py==1.10.0
    #   tox
 pycodestyle==2.7.0
    # via -r requirements/edx/testing.in
-pycontracts==1.8.12
-    # via
-    #   -r requirements/edx/base.txt
-    #   edx-user-state-client
 pycountry==20.7.3
    # via -r requirements/edx/base.txt
 pycparser==2.20
@@ -970,7 +963,6 @@ pyparsing==2.4.7
    #   chem
    #   openedx-calc
    #   packaging
-    #   pycontracts
 pyquery==1.4.3
    # via -r requirements/edx/testing.in
 pysrt==1.1.2
@@ -1189,7 +1181,6 @@ six==1.16.0
    #   isodate
    #   libsass
    #   paver
-    #   pycontracts
    #   pyjwkest
    #   python-dateutil
    #   python-memcached