1. Built-in functions
len is determined string length or number of elements
in determining whether the element belongs to the set, lists, dictionaries
not in
2. The identity of the operator
id is determined whether the two variables are equal
== determines whether the value of the variable is equal to two
3.if Process Control
if conditions:
command
elif condition:
command
else：
command
4. The variable type immutable type
Variable: In the case of the same id may change value (lists, dictionaries, collections)
Immutable: value once changed, id also changed (explain opened a new memory space)
5.while Process Control
while conditions:
command
Remove the elements in the list:
l1 = ['1','2','a','b','f','g']
a = 0
while a < len(l1):
print(l1[a])
a += 1
while and can be used in conjunction else, will execute the else statement after the while loop execution is completed
6.random random module
import random
computer = [ 'rock', 'scissors', 'cloth']
res2 = random.choice(computer)
Since part of the statement has been studied in the shell and substantially the same usage, is not repeated here
To be continued