re.match()re.match (regular expression, the string to be matched), match the regular expression from the beginning of the string, if it matches, return the match object (Match Object), otherwise return None (note that it is not an empty string "").import re print(re.match('hello','hello world')) print(re.match('world','hello world')) # <_sre.SRE_Match object; span=(0, 5), match='hello'> #NoneSingle character matchcharacterDescription[]Match any character in the brackets[^]Except for the ch

Attribute definitionDefine directly in the classclass Student(object): gender ='male'Constructor definitionclass Student(object): gender ='male' def __init__(self,name,age): self.name = name self.age = age stu = Student("BX",26) print(stu.name,stu.age,stu.gender) # BX 26 malePrivate propertyclass Student(object): gender ='male' def __init__(self,name,age,score): self.name = name self.age = age self.__score = score def getScore(self): return self.__score stu = Student("BX",26,90) print(stu.__dict

pymogoShell connection mongodb command mongo$ mongo MongoDB shell version v3.6.2 connecting to: mongodb://127.0.0.1:27017 MongoDB server version: 3.6.2 Server has startup warnings: 2018-08-05T14:29:13.960+0800 I CONTROL [initandlisten] 2018-08-05T14:29:13.960+0800 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database. 2018-08-05T14:29:13.960+0800 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted. 2018-08-05T14:29:13.960+08

pymysqlGitHub address of pymysql: https://github.com/PyMySQL/PyMySQL image.png Common data typesTypes ofByte sizeSigned range (Signed)Unsigned range (Unsigned)TINYINT1-128 ~ 1270 ~ 255SMALLINT2-32768 ~ 327670 ~ 65535MEDIUMINT3-8388608 ~ 83886070 ~ 16777215INT/INTEGER4-2147483648 ~21474836470 ~ 4294967295BIGINT8-9223372036854775808 ~ 92233720368547758070 ~ 18446744073709551615StringTypes ofByte sizeExampleCHAR0-255Type: char(3) input'ab', it is actually stored as'ab', input'abcd' is actually stor