#字符串截取
str01 = "niii hao shijie"
val01 = str01[1]
val02 = str01[0:3]
print(val01,val02)
#判断变量是否存在某个字符
b = "you"
if ("y" in b):
print("ok")
else:
print("on")
#字符串格式化
username = "小明"
age = 17
address = "北京市"
print("my is name: {name},age is: {age}, laizi is addr: {addr}".format(name=username,age=age,addr=address))
