Recursion 1
1.1 defines a function, a number of factorial
1.2 recursive function is used to print outputs of the n digital values (PS: also called rabbit Feibolaqi columns Number of columns: Starting from the third number, a number equal to the front and rear two numbers)
Function package 2
2.1 Package function to achieve the following requirements:
Example: 2,5 input print output:
2+22+222+2222+22222
2.2 determining whether a number is a prime number (neither 1 nor several prime)
2.3 calculation of the number of prime numbers is between 2 and 100, and returns the result
2.4 swap values of the variables
3 Data Types
3.1 tuple (2,3) and the set { "four", 5,6} a list of synthetic
3.2 List [3,7,5,1,8] is greater than the element 5 is set to 0, the element 5 is set to less than 1
3.3 List [ "mo", "deng", "ge"] and [2,3] is converted to [( "mo", 1), ( "deng", 2), ( "ge", 3) ]
3.4 If a = dict (), so that b = a, performing b.update ({ "x": /}), a change also, why, how to avoid
3.5 two-dimensional structure of [[ "a", /], [ "b", 2]], and (( "x", 3), ( "y", 4)) is converted into the dictionary
4 IO
4.1 package a file delete function
4.2 DESCRIPTION os.wolk () and the os.chdir () action, for example print result
5 RE（Regular Express）
5.1 verify the e-mail string is legal requirements:
① free before @ - (in bar)
Former ② @ free of ¥ & other symbols
③ may begin or comma