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【Python】int() 関数の注意点

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Python では、int() 関数を使って、整数に変換する時に一つ注意点があります。以下の例をご参照ください。

.py
>>> int(100)     #整数ー>整数、OK
100
>>> int(100.0)   #浮動小数点ー>整数、OK
100
>>> int('100')   #文字列(整数)ー>整数、OK
100
>>> int('100.0') #文字列(浮動小数点)ー>エラー
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: '100.0'

回避策の一つとしては、以下の例がご参照できます。

.py
>>> int(float('100.0'))
100

尚、float() には、このような問題はありません。

.py
>>> float(100)
100.0
>>> float('100')
100.0
>>> float('100.0')
100.0
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