Python Regular Expression Demo

1, match the case and the number, and the case number must have, and the string length is 6~20 bit

^ (? =.*\d) (? =.*[a-z]) (? =.*[a-z]) [a-za-z\d]{6,20}$

Import re
Pattern = Re.compile ("^ (? =.*\d) (? =.*[a-z]) (? =.*[a-z]) [a-za-z\d]{6,20}$])
Flag = Pattern.match ("abcDEF123")
If flag:
    Print "String matches the pattern."
Else
    Print "String doesn ' t match the pattern."

(? =.*\d): Indicates that there are numbers in the string

(? =.*[a-z]): Indicates a lowercase letter in a string

(? =.*[a-z]): Indicates that there are uppercase letters in the string

[A-za-z\d] {6,20}: Indicates that the uppercase and lowercase characters in the string and the total number of digits are 6~20
^$: Represents the beginning and end of a string, respectively


http://hlee.iteye.com/blog/327993

Python Regular Expression Demo