Python 为什么 100**0.5 == 4+6 是真的？

Question

>>> 100**0.5 != 4+6
False
>>> 100**0.5 == 4+6
True
>>> 4+6
10
>>> 100**0.5
10.0
>>> 10.0==10
True

谁能告诉我为什么 10.0==10 是 True？我认为 10.0 是 float 而 10 是 int，我知道在 java 中它们不相等。

Answer 1

引自http://docs.python.org/2/library/stdtypes.html#numeric-types-int-float-long-complex

Python fully supports mixed arithmetic: when a binary arithmetic operator has operands of different numeric types, the operand with the “narrower” type is widened to that of the other, where plain integer is narrower than long integer is narrower than floating point is narrower than complex.

因此，10 被扩展为 10.0。这就是为什么 10 == 10.0