125 lines
3.7 KiB
Python
125 lines
3.7 KiB
Python
'''
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Progress class for modules. Represents where a student is in a module.
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'''
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from collections import namedtuple
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import numbers
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class Progress(object):
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'''Represents a progress of a/b (a out of b done)
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a and b must be numeric, but not necessarily integer, with
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0 <= a <= b and b > 0.
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Progress can only represent Progress for modules where that makes sense. Other
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modules (e.g. html) should return None from get_progress().
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'''
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def __init__(self, a, b):
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'''Construct a Progress object. a and b must be numbers, and must have
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0 <= a <= b and b > 0
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'''
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# Want to do all checking at construction time, so explicitly check types
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if not (isinstance(a, numbers.Number) and
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isinstance(b, numbers.Number)):
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raise TypeError('a and b must be numbers. Passed {0}/{1}'.format(a, b))
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if not (0 <= a <= b and b > 0):
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raise ValueError(
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'fraction a/b = {0}/{1} must have 0 <= a <= b and b > 0'.format(a, b))
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self._a = a
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self._b = b
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def frac(self):
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''' Return tuple (a,b) representing progress of a/b'''
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return (self._a, self._b)
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def percent(self):
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''' Returns a percentage progress as a float between 0 and 100.
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subclassing note: implemented in terms of frac(), assumes sanity
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checking is done at construction time.
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'''
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(a, b) = self.frac()
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return 100.0 * a / b
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def started(self):
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''' Returns True if fractional progress is greater than 0.
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subclassing note: implemented in terms of frac(), assumes sanity
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checking is done at construction time.
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'''
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return self.frac()[0] > 0
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def inprogress(self):
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''' Returns True if fractional progress is strictly between 0 and 1.
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subclassing note: implemented in terms of frac(), assumes sanity
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checking is done at construction time.
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'''
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(a, b) = self.frac()
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return a > 0 and a < b
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def done(self):
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''' Return True if this represents done.
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subclassing note: implemented in terms of frac(), assumes sanity
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checking is done at construction time.
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'''
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(a, b) = self.frac()
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return a==b
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def ternary_str(self):
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''' Return a string version of this progress: either
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"none", "in_progress", or "done".
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subclassing note: implemented in terms of frac()
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'''
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(a, b) = self.frac()
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if a == 0:
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return "none"
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if a < b:
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return "in_progress"
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return "done"
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def __eq__(self, other):
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''' Two Progress objects are equal if they have identical values.
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Implemented in terms of frac()'''
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if not isinstance(other, Progress):
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return False
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(a, b) = self.frac()
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(a2, b2) = other.frac()
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return a == a2 and b == b2
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def __ne__(self, other):
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''' The opposite of equal'''
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return not self.__eq__(other)
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def __str__(self):
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''' Return a string representation of this string.
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subclassing note: implemented in terms of frac().
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'''
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(a, b) = self.frac()
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return "{0}/{1}".format(a, b)
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@staticmethod
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def add_counts(a, b):
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'''Add two progress indicators, assuming that each represents items done:
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(a / b) + (c / d) = (a + c) / (b + d).
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If either is None, returns the other.
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'''
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if a is None:
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return b
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if b is None:
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return a
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# get numerators + denominators
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(n, d) = a.frac()
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(n2, d2) = b.frac()
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return Progress(n + n2, d + d2)
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