python - 为什么 str.split 不接受关键字参数？

Question

我遇到了这个——在我看来——奇怪的行为:

"a b c".split(maxsplit=1)
TypeError: split() takes no keyword arguments

为什么 str.split() 不接受关键字参数，即使它是有意义的？我在 Python2 和 Python3 中都发现了这种行为。

Answer 1

见 this bug和 its superseder .

str.split() 是 CPython 中的原生函数，因此表现出所描述的行为 here :

CPython implementation detail: An implementation may provide built-in functions whose positional parameters do not have names, even if they are ‘named’ for the purpose of documentation, and which therefore cannot be supplied by keyword. In CPython, this is the case for functions implemented in C that use PyArg_ParseTuple() to parse their arguments.