删除额外的空字符串？

Question

假设我有一个像这样的字符串的Python列表：

x = ["", "", "test", "", "", "not empty", "", "yes", ""]

如何删除：

1. 所有领先的空字符串
2. 所有尾随空字符串
3. 所有'重复'空字符串
   （即将所有空空间值的内部序列减少为单个值）

['test', '', 'not empty', '', 'yes']

Answer 1

content = list(x.next() for i, x in it.groupby(content))
b_l_rgx = r"^(\s+)?$"
if re.match(b_l_rgx, content[0]):
    del content[0]
if len(content) > 0 and re.match(b_l_rgx, content[-1]):
    del content[-1]

Answer 2

以下是我使用dropwhile和groupby

提出的解决方案

from itertools import groupby, dropwhile

def spaces(iterable):
    it = dropwhile(lambda x: not x, iterable)
    grby = groupby(it, key=bool)
    try:
        k, g = next(grby)
    except StopIteration:
        return
    yield from g
    for k, g in grby:
        if k:
            yield ''
            yield from g

x = ["", "", "test", "", "", "not empty", "", "yes", ""]
print(list(spaces(x)))
# ['test', '', 'not empty', '', 'yes']