Files
edx-platform/xmodule/progress.py
2022-06-20 18:20:06 +05:00

136 lines
4.1 KiB
Python

'''
Progress class for modules. Represents where a student is in a module.
For most subclassing needs, you should only need to reimplement
frac() and __str__().
'''
import numbers
class Progress:
'''Represents a progress of a/b (a out of b done)
a and b must be numeric, but not necessarily integer, with
0 <= a <= b and b > 0.
Progress can only represent Progress for modules where that makes sense. Other
modules (e.g. html) should return None from get_progress().
TODO: add tag for module type? Would allow for smarter merging.
'''
def __init__(self, a, b):
'''Construct a Progress object. a and b must be numbers, and must have
0 <= a <= b and b > 0
'''
# Want to do all checking at construction time, so explicitly check types
if not (isinstance(a, numbers.Number) and
isinstance(b, numbers.Number)):
raise TypeError(f'a and b must be numbers. Passed {a}/{b}')
if a > b: # lint-amnesty, pylint: disable=consider-using-min-builtin
a = b
if a < 0: # lint-amnesty, pylint: disable=consider-using-max-builtin
a = 0
if b <= 0:
raise ValueError(f'fraction a/b = {a}/{b} must have b > 0')
self._a = a
self._b = b
def frac(self):
''' Return tuple (a,b) representing progress of a/b'''
return (self._a, self._b)
def percent(self):
''' Returns a percentage progress as a float between 0 and 100.
subclassing note: implemented in terms of frac(), assumes sanity
checking is done at construction time.
'''
(a, b) = self.frac()
return 100.0 * a / b
def started(self):
''' Returns True if fractional progress is greater than 0.
subclassing note: implemented in terms of frac(), assumes sanity
checking is done at construction time.
'''
return self.frac()[0] > 0
def inprogress(self):
''' Returns True if fractional progress is strictly between 0 and 1.
subclassing note: implemented in terms of frac(), assumes sanity
checking is done at construction time.
'''
(a, b) = self.frac()
return a > 0 and a < b # lint-amnesty, pylint: disable=chained-comparison
def done(self):
''' Return True if this represents done.
subclassing note: implemented in terms of frac(), assumes sanity
checking is done at construction time.
'''
(a, b) = self.frac()
return a == b
def ternary_str(self):
''' Return a string version of this progress: either
"none", "in_progress", or "done".
subclassing note: implemented in terms of frac()
'''
(a, b) = self.frac()
if a == 0:
return "none"
if a < b:
return "in_progress"
return "done"
def __eq__(self, other):
''' Two Progress objects are equal if they have identical values.
Implemented in terms of frac()'''
if not isinstance(other, Progress):
return False
(a, b) = self.frac()
(a2, b2) = other.frac()
return a == a2 and b == b2
def __ne__(self, other):
''' The opposite of equal'''
return not self.__eq__(other)
def __str__(self):
'''Return a string representation of this string. Rounds results to
two decimal places, stripping out any trailing zeroes.
subclassing note: implemented in terms of frac().
'''
(a, b) = self.frac()
display = lambda n: f'{n:.2f}'.rstrip('0').rstrip('.')
return f"{display(a)}/{display(b)}"
@staticmethod
def add_counts(a, b):
'''Add two progress indicators, assuming that each represents items done:
(a / b) + (c / d) = (a + c) / (b + d).
If either is None, returns the other.
'''
if a is None:
return b
if b is None:
return a
# get numerators + denominators
(n, d) = a.frac()
(n2, d2) = b.frac()
return Progress(n + n2, d + d2)