基本语法之for循环

目录

• for循环
  • for + break的语法
  • for + continue的语法
  • for + else的语法

for循环

循环：重复干一件事，循环容器数据类型

lis = ['gebilaowang', 'dapao', 'yongjiushuaige','dsb']
print(len(lis))

count = 0
while True:
    if count == len(lis):
        break
    print(lis[count])
    count += 1
    
'''
while:
    1. 会进入死循环(不可控),尽量少使用while循环
    2. 世间万物都可以作为循环的对象
for:
    1. 不会进入死循环(可控),以后尽量使用for循环
    2. 只对容器类数据类型+字符串循环(可迭代对象)

'''

lis = ['gebilaowang', 'dapao', 'yongjiushuaige','dsb']

for i in lis:  # i='gebilaowang'  # i='dapao'
    print(i)  # i='gebilaowang'  # i='dapao'
    print(1)

    
for i in 'nick':
    print(i)


print(list(range(3)))  # 0,1,2
print(list(range(10)))  # 0,1,2..9
print(list(range(2,5)))  # 2,3,4  # 顾头不顾尾
print(list(range(3,6)))  # 3,4,5  # 顾头不顾尾


print(list(range(3,7,3)))  # 3,6  # 顾头不顾尾
print(list(range(1,10,2)))  # 1,3,5,7,9  # 顾头不顾尾

for + break的语法

for i in range(1,11): # 1,2,3,4,5
    print(i)
    if i == 5:
        break  #跳出循环

for + continue的语法

for i in range(1,11):  # 1,2,3,4,5,6,7,8,9,10
    if i == 5:
        continue   # 跳出本次循环
    print(i)

for + else的语法

for i in range(1,11): # 1,2,3,4,6,7,8,9,10
    if i == 5:
        break  #跳出本次循环

    print(i)
else:  # 没有被break会触发
    print('hello,你居然运行到了else')

eg:

import time

print('Loading',end='')

for i in range(6):
    print('.',end='')   # ......
    time.sleep(0.5)