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Question

在python中，我如何在遇到'-‘的地方将一个长列表拆分成一个列表列表。例如，如何转换：

['1', 'a', 'b','---', '2','c','d','---','3','123','e','---','4']

至

[['1', 'a', 'b'],['2','c','d'],['3','123','e'],['4']]

在此之前，非常感谢您。

Answer 1

In [17]: import itertools
# putter around 22 times
In [39]: l=['1', 'a', 'b','---', '2','c','d','---','3','123','e','---','4']

In [40]: [list(g) for k,g in itertools.groupby(l,'---'.__ne__) if k]
Out[40]: [['1', 'a', 'b'], ['2', 'c', 'd'], ['3', '123', 'e'], ['4']]

Answer 2

import itertools

l = ['1', 'a', 'b','---', '2','c','d','---','3','123','e','---','4']
r = []

i = iter(l)
while True:
  a = [x for x in itertools.takewhile(lambda x: x != '---', i)]
  if not a:
    break
  r.append(a)
print r

# [['1', 'a', 'b'], ['2', 'c', 'd'], ['3', '123', 'e'], ['4']]

Answer 3

import itertools

a = ['1', 'a', 'b','---', '2','c','d','---','3','123','e','---','4']
b = [list(x[1]) for x in itertools.groupby(a, '---'.__eq__) if not x[0]]

print b     # or print(b) in Python 3

结果是

[['1', 'a', 'b'], ['2', 'c', 'd'], ['3', '123', 'e'], ['4']]