Python collections 判断实例是否为可迭代对象或迭代器

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collections 判断实例是否为可迭代对象或迭代器

from collections.abc import Iterable

# 可迭代对象中需要实现 __iter__ 或者 __getitem__
# list() 是 可迭代对象吗？
isinstance(list(),Iterable)

True

from collections.abc import Iterator

# 迭代器 __iter__ __next__ stopiteration
# list()是迭代器吗？
isinstance(list(),Iterator)

False

# iter(list())是迭代器吗？
isinstance(iter(list()),Iterator)

True

help

help(iter)

Help on built-in function iter in module builtins:

iter(...)
    iter(iterable) -> iterator
    iter(callable, sentinel) -> iterator
    
    Get an iterator from an object.  In the first form, the argument must
    supply its own iterator, or be a sequence.
    In the second form, the callable is called until it returns the sentinel.

help(Iterator)

elp on class Iterator in module collections.abc:

class Iterator(Iterable)
 |  Method resolution order:
 |      Iterator
 |      Iterable
 |      builtins.object
 |  
 |  Methods defined here:
 |  
 |  __iter__(self)
 |  
 |  __next__(self)
 |      Return the next item from the iterator. When exhausted, raise StopIteration

......

help(Iterable)

Help on class Iterable in module collections.abc:

class Iterable(builtins.object)
 |  Methods defined here:
 |  
 |  __iter__(self)

......

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