遗憾的是，Python没有一个简单的方法来平展列表。试试这个:

def flatten(some_list):
    for element in some_list:
        if type(element) in (tuple, list):
            for item in flatten(element):
                yield item
        else:
            yield element

它将递归地将列表平展;你可以这样做

result = []
[ result.extend(el) for el in x] 

for el in flatten(result):
      print el

这就是所谓的扁平化，有很多实现。

这个怎么样，尽管它只适用于1级深嵌套:

>>> x = [["a","b"], ["c"]]
>>> for el in sum(x, []):
...     print el
...
a
b
c

从这些链接中，显然最完整的-fast-elegant-etc实现如下:

def flatten(l, ltypes=(list, tuple)):
    ltype = type(l)
    l = list(l)
    i = 0
    while i < len(l):
        while isinstance(l[i], ltypes):
            if not l[i]:
                l.pop(i)
                i -= 1
                break
            else:
                l[i:i + 1] = l[i]
        i += 1
    return ltype(l)

您所描述的就是所谓的将列表扁平化，有了这些新知识，您将能够在谷歌上找到许多解决方案(没有内置的扁平化方法)。以下是其中一个，来自http://www.daniel-lemire.com/blog/archives/2006/05/10/flattening-lists-in-python/:

def flatten(x):
    flat = True
    ans = []
    for i in x:
        if ( i.__class__ is list):
            ans = flatten(i)
        else:
            ans.append(i)
    return ans

如果你只深入一层，一个嵌套的理解也可以:

>>> x = [["a","b"], ["c"]]
>>> [inner
...     for outer in x
...         for inner in outer]
['a', 'b', 'c']

在一行上，它变成:

>>> [j for i in x for j in i]
['a', 'b', 'c']

import itertools
a = [['a','b'], ['c']]
print(list(itertools.chain.from_iterable(a)))

这给了

['a', 'b', 'c']

遗憾的是，Python没有一个简单的方法来平展列表。试试这个:

def flatten(some_list):
    for element in some_list:
        if type(element) in (tuple, list):
            for item in flatten(element):
                yield item
        else:
            yield element

它将递归地将列表平展;你可以这样做

result = []
[ result.extend(el) for el in x] 

for el in flatten(result):
      print el