spy#

more_itertools.spy(iterable, n=1)

Пример

In [19]: def file_gen(filename):
    ...:     with open(filename) as f:
    ...:         for idx, line in enumerate(f):
    ...:             print(idx)
    ...:             yield line
    ...:

In [20]: f = file_gen('sh_cdp_neighbors_detail.txt')

In [21]: f
Out[21]: <generator object file_gen at 0xb28bd4ec>

In [23]: first, f = more_itertools.spy(f)
0

In [24]: first
Out[24]: ['SW1#show cdp neighbors detail\n']

In [25]: f
Out[25]: <itertools.chain at 0xb38c184c>

In [26]: next(f)
Out[26]: 'SW1#show cdp neighbors detail\n'