2while

一.while

1.while 死循环

f=True
while f:
    print(1)
print(2)

2.while 活循环

①.正序

count = 1
while count <= 5:
    print(count)
    count += 1

②.倒序

count=5
while count:
    print(count)
    count-=1

3.break continue

while True:
    print(1)
    print(2)
    break
    print(3)
print(4)

1
2
4

while True:    print(1)    print(2)    continue    print(3)print(4)1212...

4.若果 循环 否则 while else

while True:    print(1)    breakelse:    print(2)

二.数字里非零的都是Ture

print(bool(0))

三.字符串的格式化

1.项目—名片

用户输入的内容和开发者预留的内容拼接 然后一起输出的方法

①.加法拼接

a="name:"b="age:"c="job:"d=input("名:")e=input("龄:")f=input("工:")print(a+d+"\n"+b+e+"\n"+c+f)

②.字符串格式化拼接

m='''name:%sage:%sjob:%s'''a=input("名：")b=input("龄:")c=input("工:")print(m%(a,b,c))

m='''name:%sage:%djob:%s'''a=input("名：")b=int(input("龄:"))c=input("工:")print(m%(a,b,c))

③要输出一句 A层1 以下四种方法

b=input("输:")a="A层:"print(a+b)

b=input("输:")a="A层：%s"print(a%(b))

a=f"A层{1}"print(b)

b=input("层：")a=f"A层{b}"print(a)

四.运算符

1.赋值运算符

①.自加

a=10a+=1print(a)

②.自乘

a=10a*=2print(a)

2.逻辑运算符

①. and 安真后 安假钱 安逸假

print(0 and 1)

②.or 傲真浅 傲假吼 奥义真

print(0 or 1)

③.优先级: ()>not>and>or

print(9 and 1 or not False and 8 or 0 and 7 and False)

3.成员运算符 in not in

s="als"print("ls" in s)True

s="als"if "ls" in s:    print(True)else:    print(False)    True