time,random,datetime
import time print(time.time())
import random
from random import randint
random.choice
import datetime
year = datetime.datetime.now().year
month = datetime.datetime.now().month
print(year , month)
a=2
b=8
c=9
a,b,c = c,a,b # 变量交换
print(a,b,c)
tuple = (1,2,3,4) # 元组
print(tuple[1:3]) # (2, 3)
tuple[2]=3 # 出错,tuple不能修改
st1,st2,st3 = (1,2,3) # 等效于 st1,st2,st3 = 1,2,3 如果不加括号,将会被自动视为元组
print(st1,st2,st3,sep=' & ') # 1 & 2 & 3
mylist = [3,'this',6.2]
mylist.extend([3,4])
print(mylist)
mylist.pop()
print(mylist)
print(mylist.index('this'))
mylist.sort()
print(mylist)