fractions模塊可以用來處理涉及分數的數學計算問題
from fractions import Fraction
a = Fraction(5,4)
b = Fraction(7, 16)
print (a+b)
#27/16
print (a*b)
#35/64
#獲取分子和分母
c = a*b
print (c.numerator)
#35
print (c.denominator)
#64
#轉換成浮點數
f = float(c)
print (f)
#0.546875
#limiting the denominator
print (c.limit_denominator(8))
#4/7
#converting a float to a fraction
x = 3.75
y = Fraction(*x.as_integer_ratio())
print (y)
#15/4
