小数の比較.py

fraction.py

# a/b == Fraction(a,b) 有理数計算クラス
from fractions import Fraction
from decimal import Decimal


def f(a, x, y):
    print("a, x, y,", a, ",",  x, ",", y)
    a = int(a)
    x = int(x) # 1e16 + 1
    y = int(y) # 1e16 + 2
    # int型のまま
    if a/x == a/y: print("/       : a/x == a/y")
    if a/x >  a/y: print("/       : a/x >  a/y")
    if a/x  < a/y: print("/       : a/x  < a/y")
    # Decimal型で割り算
    da, dx, dy = Decimal(a), Decimal(x), Decimal(y)
    if da/dx == da/dy: print("Decimal : a/x == a/y")
    if da/dx >  da/dy: print("Decimal : a/x >  a/y")
    if da/dx  < da/dy: print("Decimal : a/x  < a/y")
    # Fractionクラスで割り算
    if Fraction(a, x) == Fraction(a, y): print("Fraction: a/x == a/y")
    if Fraction(a, x) >  Fraction(a, y): print("Fraction: a/x >  a/y")
    if Fraction(a, x)  < Fraction(a, y): print("Fraction: a/x  < a/y")
    # 通分する
    if a*y == a*x: print("Common  : a/x == a/y (means: a*y == a*x)")
    if a*y >  a*x: print("Common  : a/x >  a/y (means: a*y >  a*x)")
    if a*y  < a*x: print("Common  : a/x  < a/y (means: a*y  < a*x)")

print("Python")
f("1", "10000000000000001", "10000000000000002")
f("1", "10000000000000003", "10000000000000004")
f("5", "10000000000000001", "10000000000000002")
f("5", "10000000000000003", "10000000000000004")