pythonRegex1，pythonRegex

pythonRegex1，pythonRegex

使用Regex，需要匯入re這個模組

1 >>> import re2 >>> pattern=r'abc'3 >>> str='abcdefghijabc11111abc'4 >>> re.findall( pattern, str )5 ['abc', 'abc', 'abc']6 >>> 

r定義Regex的規則，這裡匹配abc這個字串

元字元（[]）匹配一個範圍

>>> str="abc afc awc">>> pattern=r"a[bfw]c">>> re.findall( pattern, str )['abc', 'afc', 'awc']>>> pattern=r"a[bf]w">>> re.findall( pattern, str )[]>>> pattern=r"a[bf]c">>> re.findall( pattern, str )['abc', 'afc']>>> 

^：以...開頭，用在中括弧裡面表示非(取反，或者說排除)

1 >>> import re2 >>> str="ghostwu:hi my name is ghostwu, nice to meet you!"3 >>> pattern=r"ghostwu"4 >>> re.findall( pattern, str )5 ['ghostwu', 'ghostwu']6 >>> pattern=r"^ghostwu"7 >>> re.findall( pattern, str )8 ['ghostwu']9 >>> 

1 >>> str="abc"2 >>> pattern=r"a[b]c"3 >>> re.findall( pattern, str )4 ['abc']5 >>> pattern=r"a[^b]c"6 >>> re.findall( pattern, str )7 []8 >>> 

$:以....結尾

>>> str="ghostwu:hi my name is ghostwu, nice to meet you! Hanmeimei: Hi,ghostwu">>> pattern=r"ghostwu">>> re.findall( pattern, str )['ghostwu', 'ghostwu', 'ghostwu']>>> pattern=r"ghostwu$">>> re.findall( pattern, str )['ghostwu']>>> 

$在中括弧中被當做普通的字串匹配

 1 >>> pattern=r"a[bcd$]" 2 >>> re.findall( pattern, 'ab' ) 3 ['ab'] 4 >>> re.findall( pattern, 'ac' ) 5 ['ac'] 6 >>> re.findall( pattern, 'ad' ) 7 ['ad'] 8 >>> re.findall( pattern, 'abe' ) 9 ['ab']10 >>> re.findall( pattern, 'a$' )11 ['a$']12 >>> 

逸出字元 \

 1 >>> str="^ghostwu ^ghostwu ^ghostwu" 2 >>> pattern=r"^ghostwu" 3 >>> re.findall( pattern, str ) 4 [] 5 >>> pattern=r"ghostwu" 6 >>> re.findall( pattern, str ) 7 ['ghostwu', 'ghostwu', 'ghostwu'] 8 >>> pattern=r"\^ghostwu" 9 >>> re.findall( pattern, str )10 ['^ghostwu', '^ghostwu', '^ghostwu']11 >>>