为了说明,我从一个 2 元组列表开始:
import itertools
import operator
raw = [(1, "one"),
(2, "two"),
(1, "one"),
(3, "three"),
(2, "two")]
for key, grp in itertools.groupby(raw, key=lambda item: item[0]):
print key, list(grp).pop()[1]
产量:
1 one
2 two
1 one
3 three
2 two
试图调查原因:
for key, grp in itertools.groupby(raw, key=lambda item: item[0]):
print key, list(grp)
# ---- OUTPUT ----
1 [(1, 'one')]
2 [(2, 'two')]
1 [(1, 'one')]
3 [(3, 'three')]
2 [(2, 'two')]
即使这会给我相同的输出:
for key, grp in itertools.groupby(raw, key=operator.itemgetter(0)):
print key, list(grp)
我想得到类似的东西:
1 one, one
2 two, two
3 three
我认为这是因为键在列表内的元组内,而实际上元组作为一个移动。有没有办法达到我想要的输出?也许groupby()
不适合这个任务?