问题
How can I loop through all the elements in a list of tuples, into an empty list?
For example:
tup_Before = [(69592, 69582), (69582, 69518), (69518, 69532), (69532, 69525)]
tup_After = [69592, 69582, 69582, 69518, 69518, 69532, 69532, 69525]
回答1:
A list comprehension:
tup_after = [v for t in tup_Before for v in t]
or use itertools.chain.from_iterable():
from itertools import chain
tup_after = list(chain.from_iterable(tup_Before))
Demo:
>>> tup_Before = [(69592, 69582), (69582, 69518), (69518, 69532), (69532, 69525)]
>>> [v for t in tup_Before for v in t]
[69592, 69582, 69582, 69518, 69518, 69532, 69532, 69525]
>>> from itertools import chain
>>> list(chain.from_iterable(tup_Before))
[69592, 69582, 69582, 69518, 69518, 69532, 69532, 69525]
回答2:
also, the least clear answer:
[l for l in l for l in l]
where l is your list name
回答3:
You can try using itertools.chain() and unpacking with *:
import itertools
new_tup = list(itertools.chain(*tup_before))
Demo:
>>> print new_tup
[69592, 69582, 69582, 69518, 69518, 69532, 69532, 69525]
来源：https://stackoverflow.com/questions/22643557/flattening-a-list-of-tuples