136 lines
4.4 KiB
Python
136 lines
4.4 KiB
Python
#stores a rational number to perfect precision as a ratio of longs
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#combines with ints to produce a frac ( except __rpow__() ) and with floats to produce a float
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#comparisons with floats might not work perfectly for very similar numbers, I need to test out the float casting a bit
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#it's possible that order w/r/t floats that differ near the limit of precision may not work properly, and even break ordering
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#one solution would be casting floats to fracs instead of vice-versa
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import numbers
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class frac:
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def __init__(self, num, den):
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self.num = long(num)
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self.den = long(den)
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self.reduce()
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def __repr__(self):
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return 'frac(%d, %d)' % (self.num, self.den)
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def __str__(self):
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return '%d/%d' % (self.num, self.den)
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def __int__(self):
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return int(self.num / self.den)
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def __long__(self):
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return self.num / self.den
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def __float__(self):
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return float(self.num) / self.den
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def __bool__(self):
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return bool(self.num)
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def __add__(self, other):
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if isinstance(other, frac):
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newnum = self.num * other.den + other.num * self.den
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newden = self.den * other.den
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return frac(newnum, newden)
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elif isinstance(other, (int, long)):
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return frac(self.num + other * self.den, self.den)
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elif isinstance(other, float):
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return other + float(self)
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else:
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return NotImplemented
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def __radd__(self, other):
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return self + other
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def __sub__(self, other):
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if isinstance(other, frac):
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newnum = self.num * other.den - other.num * self.den
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newden = self.den * other.den
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return frac(newnum, newden)
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elif isinstance(other, (int, long)):
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return frac(self.num - other * self.den, self.den)
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elif isinstance(other, float):
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return float(self) - other
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else:
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return NotImplemented
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def __rsub__(self, other):
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return -1 * (self - other)
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def __mul__(self, other):
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if isinstance(other, frac):
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return frac(self.num * other.num, self.den * other.den)
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elif isinstance(other, (int, long)):
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return frac(self.num * other, self.den)
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elif isisntance(other, float):
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return float(self) * other
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else:
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return NotImplemented
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def __rmul__(self, other):
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return self * other
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def __truediv__(self, other):
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if isinstance(other, frac):
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return frac(self.num * other.num, self.den * other.den)
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elif isintance(other, (int, long)):
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return frac(self.num * other, self.den)
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elif isinstance(other, float):
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return float(self) * other
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else:
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return NotImplemented
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def __rtruediv__(self, other):
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if isinstance(other, frac):
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return frac(other.num * self.den, self.num * other.den)
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elif isinstance(other, (int, long)):
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return frac(self.den * other, self.num)
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elif isinstance(other, float):
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return other / float(self)
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else:
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return NotImplemented
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def __pow__(self, other):
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if isinstance(other, frac):
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return float(self) ** float(other)
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elif isinstance(other, (int, long)):
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return frac(self.num ** other, self.den ** other)
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elif isinstance(other, float):
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return float(self) ** other
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else:
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return NotImplemented
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def __rpow__(self, other):
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if isinstance(other, frac):
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return float(other) ** float(self)
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elif isinstance(other, (int, long)):
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return other ** float(self)
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elif isinstance(other, float):
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return other ** float(self)
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else:
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return NotImplemented
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def __lt__(self, other):
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if isinstance(other, frac):
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return self.num * other.den < other.num * self.den
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else:
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return float(self) < other
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def __le__(self, other):
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if isinstance(other, frac):
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return self.num * other.den <= other.num * self.den
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else:
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return float(self) <= other
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def __eq__(self, other):
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if isinstance(other, frac):
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return self.num * other.den == other.num * self.den
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else:
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return float(self) == other
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def reduce(self):
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pass |