findall

查詢所有匹配項，返回的是一個列表

import re
re.findall("\d+", "alex12lucy22")
# ["12", "22"]

search

只返回第一次匹配項，返回一個group物件

import re
re.search("\d+", "alex12lucy22").group()
# "12"

match

只在開始位置匹配一次

import re
re.match("\d+", "alex12lucy22").group()
#
re.match("[a-z]+", "alex12lucy22").group()
# "alex"
 

split

import re
re.split("[ab]", "ahighabwest")
# 按照a分割成 ['', 'high', 'bwest']
# 再按照b分割成['', 'high', '', 'west']
# ['', 'high', '', 'west']

sub

字串替換

import re
re.sub("\d+", "dog", "You 666!")
# 'You dog!'

import re
re.sub("\d+", "dog", "You 666 999!")
# 'You dog dog!'
re.sub("\d+", "dog", "You 666 999!", 1)
# 'You dog 999!'
 

subn

返回一個元組，包括替換後的字串和替換次數

import re
re.subn("\d+", "dog", "You 666 999!", 1)
# ('You dog 999!', 1)

compile

一個正則表示式方便多次使用

import re
reg = re.compile("\d+")
reg.search("lucy22cuci19")
# <re.Match object; span=(4, 6), match='22'>
reg.search("lucy22cuci19").group()
# '22'
reg.search("wanjia29xifeng36")
# <re.Match object; span=(6, 8), match='29'>
reg.search("wanjia29xifeng36").group()
# '29'
 

finditer

返回一個遍歷器物件

import re
arr = re.finditer("\d+", "lucy22cuci19")
next(arr).group()
# '22'