1.re.match
re.match尝试从字符创的起始位置匹配一个模式,如果不是起始位置匹配成功的话,就会返回None。
re.match(pattern,string,flags=0)
2.最常规的匹配
import re
content = 'Hello 123 4567 World_This is a Regex Demo'
result = re.match('^Hello\s\d{3}\s\d{4}\s\w{10}.*Demo$',content)
print(result)
3.范匹配
import re
content = 'Hello 123 4567 World_This is a Regex Demo'
result = re.match('^Hello.*Demo$',content)
print(result)
print(result.group())
print(result.span())
4.匹配目标
import re
content = 'Hello 1234567 World_This is a Regex Demo'
result = re.match('Hello\s(\d+)\sWorld.*Demo$',content)
print(result)
print(result.group(1))
print(result.span())
5.贪婪匹配
import re
content = 'Hello 1234567 World_This is a Regex Demo'
result = re.match('^He.*(\d+).*Demo$',content)
print(result)
print(result.group(1))
print(result.span())
6.非贪婪模式
import re
content = 'Hello 1234567 World_This is a Regex Demo'
result = re.match('^He.*?(\d+).*Demo$',content)
print(result)
print(result.group(1))
print(result.span())
7.匹配模式
import re
content = 'Hello 1234567 World_This
is a Regex Demo'
result = re.match('^He.*?(\d+).*Demo$',content,re.S)
print(result)
print(result.group(1))
print(result.span())
8.转义
import re
content = 'price is $500'
result = re.match('price is $500',content)
print(result)
#结果为None
import re
content = 'price is $5.00'
result = re.match('price is \$5\.00',content)
print(result)#有结果
tip:尽量使用范匹配,使用括号得到匹配目标,尽量使用非贪婪模式,有换行符就用re.S
9.re.search
re.search扫描整个字符串并返回第一个成功的匹配
import re
content = 'Extra stings Hello 1234567 World_This is a Regex Demo Extra stings'
result = re.match('Hello.*?(d+).*?Demo',content)
print(result)#结果为None
import re
content = 'Extra stings Hello 1234567 World_This is a Regex Demo Extra stings'
result = re.search('Hello.*?(\d+).*?Demo',content)
print(result.group(1))#结果为1234567
10.re.findall
搜索字符串,以列表形式返回全不能匹配的字符串。
11.re.sub
替换字符串中每一个匹配的字符串后返回替换的字符串。
import re
content = 'Extra stings Hello 1234567 World_This is a Regex Demo Extra stings'
content = re.sub('\d+',content)
print(content)