如何在Python中指定文字生成器类型？

Question

I need to check if a certain variable is a generator object. How would I specify the literal generator type in place of the ??? below?

def go():
    for i in range(999):
    yield i
la = go()
print repr(type(la))

<type 'generator'>

assert type(la) == ???

Answer 1

Use types.GeneratorType (from the types module). You should think, though, about why you're doing this. It's usually better to avoid explicit type-checking and just try iterating over the object and see if it works.

Answer 2

import types
assert isinstance(la, types.GeneratorType)

Answer 3

In general you wouldn't. You'd look for attributes with the names of __iter__ and next , both functions.