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cpython/Demo/classes/Rat.py
1992-08-13 12:14:11 +00:00

87 lines
1.4 KiB
Python
Executable File

# Rational numbers
def rat(num, den):
return Rat().init(num, den)
def gcd(a, b):
while b:
a, b = b, a%b
return a
class Rat:
def init(self, num, den):
if den == 0:
raise ZeroDivisionError, 'rat(x, 0)'
g = gcd(num, den)
self.num = num/g
self.den = den/g
return self
def __repr__(self):
return 'rat' + `self.num, self.den`
def __cmp__(a, b):
c = a-b
if c.num < 0:
return -1
if c.num > 0:
return 1
return 0
def __float__(self):
return float(self.num) / float(self.den)
def __long__(self):
return long(self.num) / long(self.den)
def __int__(self):
return int(self.num / self.den)
def __coerce__(a, b):
t = type(b)
if t == type(0):
return a, rat(b, 1)
if t == type(0L):
return a, rat(b, 1L)
if t == type(0.0):
return a.__float__(), b
raise TypeError, 'Rat.__coerce__: bad other arg'
def __add__(a, b):
return rat(a.num*b.den + b.num*a.den, a.den*b.den)
def __sub__(a, b):
return rat(a.num*b.den - b.num*a.den, a.den*b.den)
def __mul__(a, b):
return rat(a.num*b.num, a.den*b.den)
def __div__(a, b):
return rat(a.num*b.den, a.den*b.num)
def __neg__(self):
return rat(-self.num, self.den)
def test():
print rat(-1L, 1)
print rat(1, -1)
a = rat(1, 10)
print int(a), long(a), float(a)
b = rat(2, 5)
l = [a+b, a-b, a*b, a/b]
print l
l.sort()
print l
print rat(0, 1)
print rat(1, 0)
print a+1
print a+1L
print a+1.0
test()