Python Decimal

Python Decimal

[Python] Python Osmosis

Decimal

• from decimal で利用
• 小数点以下の計算も正しく行う
• getcontext().prec で有効桁数を設定

Python 2.6.3 (r263rc1:75186, Oct  2 2009, 20:40:30) [MSC v.1500 32 bit (Intel)] on win32
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>>> from decimal import *
>>> Decimal('0.70') * Decimal('1.05')
Decimal('0.7350')
>>> .70 * 1.05
0.73499999999999999
>>> Decimal('1.00') % Decimal('.10')
Decimal('0.00')
>>> 1.00 % 0.10
0.09999999999999995
>>> sum([Decimal('0.1')] * 10) == Decimal('1.0')
True
>>> sum([0.1] * 10) == 1.0
False
>>> getcontext().prec = 36
>>> Decimal(1) / Decimal(7)
Decimal('0.142857142857142857142857142857142857')