1 import re 2 3 print (re.findall( ' s...t ' , ' rhjioestastgih ' )) #One . Represents matching a character 4 5 # * Matching 0 to infinite times (0,+00) means not Match at least 0, but a character before * can not match 6 #Example # ['sk'] 7 print (re.findall( ' skt* ' , ' skeriuhgioerg ' )) 8 9 # + match 1 time to infinity Times (1,+00) means that it does not match at least 1, but all characters before + must match 10 # Example#[] 11 print (re.findall( 'skt+','skeriuhgioerg')) 12 13 print(re.findall('stc*','uwhdefoistttttt')) #['st'] 14 print(re.findall('stc+','uwhdefoistttttt')) #[] 15 16 print(re.findall('st{0,1}','eriufhstfkjh')) 17 print(re.findall('stc*','uwhdefoistttttt')) #['st'] 18 print(re.findall('stc+','uwhdefoistttttt')) #[] 19 20 ret=re.findall('abc?','abccc')#[0,1] 21 print(ret)#['abc'] 22 23 print(re.findall('stt*?','stttttttttt' )) #Lazy matching ['st'] 24 print (re.findall( ' stt +? ' , ' stttttttttt ' )) #Lazy matching ['stt'] 25 26 print (re.findall( ' skt? ' , ' iuhskuirh ' )) # ?[0,1] The previous one can not match, only one match if there is a match #['sk'] 27 print (re.findall( ' skt? ' , ' iuhsktttuirh ' )) # ['skt '] 28 29 30ret=re.findall( ' abc{1,4} ' , ' abccccccc ' ) # The last digit of {x,y} can be matched at least x times and at most y times 31 print (ret) # ['abccc'] Greedy matching 32 33 print (re.findall( ' [0-9] ' , ' qq5ds5sg1r56ee2g ' )) # [0-9] means any number up to 0123456789, or 34 print (re.findall( ' [0 -9]* ' , ' qq55g876h5 ' )) 35 print (re.findall( ' [az]' , ' qqa ' )) 36 print (re.findall( ' [AZ]* ' , ' qqSOIGNIOSDF ' )) 37 print (re.findall( ' [^AZ]* ' , ' qqS1O23IGNIOSDF ' )) # [^] Indicates that non-reversed does not contain 38 39 # # The escape character of meta-characters \ 40 # # The backslash is followed by meta-characters to remove special functions, such as \. 41 # # The backslash is followed by ordinary characters to realize special functions, such as \ d 42 # # 43 # # \d matches any decimal number; it is equivalent to the class [0-9]. 44 ## \D matches any non-numeric character; it is equivalent to the class [^0-9]. 45 # # \s matches any whitespace character; it is equivalent to the class [ \t\n\r\f\v]. 46 # # \S matches any non-whitespace character; it is equivalent to the class [^ \t\n\r\f\v]. 47 # # \w matches any alphanumeric character; it is equivalent to the class [a-zA-Z0-9_]. 48 # # \W matches any non-alphanumeric character; it is equivalent to the class [^a-zA-Z0-9_] 49 # # \b matches a special character boundary such as space, &, #, etc.