在Python中查找列表中的子字符串

Question

背景:

示例列表: mylist = ['abc123', 'def456', 'ghi789']

如果匹配子字符串,我想检索一个元素,比如 abc

码:

sub = 'abc'
print any(sub in mystring for mystring in mylist)

True如果列表中的任何元素包含模式,则上面打印.

我想打印匹配子字符串的元素.所以,如果我正在检查'abc'我只想'abc123'从列表中打印.

Answer 1

print [s for s in list if sub in s]

如果您希望它们以换行符分隔:

print "\n".join(s for s in list if sub in s)

完整示例,不区分大小写:

mylist = ['abc123', 'def456', 'ghi789', 'ABC987', 'aBc654']
sub = 'abc'

print "\n".join(s for s in mylist if sub.lower() in s.lower())

Answer 2

所有答案都有效,但它们总是遍历整个列表.如果我理解你的问题,你只需要第一场比赛.因此,如果您找到第一场比赛,则无需考虑列表的其余部分:

mylist = ['abc123', 'def456', 'ghi789']
sub = 'abc'
next((s for s in mylist if sub in s), None) # returns 'abc123'

如果匹配位于列表的末尾或非常小的列表,则它没有区别,但请考虑以下示例:

import timeit

mylist = ['abc123'] + ['xyz123']*1000
sub = 'abc'

timeit.timeit('[s for s in mylist if sub in s]', setup='from __main__ import mylist, sub', number=100000)
# for me 7.949463844299316 with Python 2.7, 8.568840944994008 with Python 3.4
timeit.timeit('next((s for s in mylist if sub in s), None)', setup='from __main__ import mylist, sub', number=100000) 
# for me 0.12696599960327148 with Python 2.7, 0.09955992100003641 with Python 3.4

Answer 3

使用简单的for循环:

seq = ['abc123', 'def456', 'ghi789']
sub = 'abc'

for text in seq:
    if sub in text:
        print(text)

产量

abc123

Answer 4

这将打印包含sub的所有元素:

for s in filter (lambda x: sub in x, list): print (s)

Answer 5

我只是使用一个简单的正则表达式,你可以做这样的事情

import re
old_list = ['abc123', 'def456', 'ghi789']
new_list = [x for x in old_list if re.search('abc', x)]
for item in new_list:
    print item