python - isinstance(foo, types.GeneratorType) 还是 inspect.isgenerator(foo)？

Question

在Python中似乎有两种方法来测试一个对象是否是生成器:

import types
isinstance(foo, types.GeneratorType)

或:

import inspect
inspect.isgenerator(foo)

本着“应该有一种 - 最好只有一种 - 显而易见的方法”的精神，推荐这些方法中的一种而不是另一种(大概他们做同样的事情......如果不是，请赐教!)？

Answer 1

它们是 100% 等效的:

>>> print(inspect.getsource(inspect.isgenerator))
def isgenerator(object):
    """Return true if the object is a generator.

    Generator objects provide these attributes:
        __iter__        defined to support interation over container
        close           raises a new GeneratorExit exception inside the
                        generator to terminate the iteration
        gi_code         code object
        gi_frame        frame object or possibly None once the generator has
                        been exhausted
        gi_running      set to 1 when generator is executing, 0 otherwise
        next            return the next item from the container
        send            resumes the generator and "sends" a value that becomes
                        the result of the current yield-expression
        throw           used to raise an exception inside the generator"""
    return isinstance(object, types.GeneratorType)

我会说使用 isinstance(object, types.GeneratorType) 应该是首选方式，因为它更清晰、更简单。另外inspect.isgenerator是python2.6才加入的，这意味着使用isinstance更加向后兼容。

他们可能为对称添加了isgenerator 函数isgeneratorfunction它做了一些不同的事情。