python基础学习笔记——循环语句(while、for)

while 条件:
      
    # 循环体
  
    # 如果条件为真，那么循环则执行
    # 如果条件为假，那么循环不执行

num = 1
while num <6:
    print(num)
    num+=1
    break
    print("end")

num = 1
while num <6:
    print(num)
    num+=1
    continue
    print("end")

while True:
    if 3 > 2:
        print(‘你好‘)
        break
else:
    print(‘不好‘)
while True:
    if 3 > 2:
        print(‘你好‘)
print(‘不好‘)
 
# 大家看到的这个是不是感觉效果是一样的啊,其实不然
# 当上边的代码执行到break的时候else缩进后的内容不会执行

#for循环主要用来遍历、循环、序列、集合、字典
Fruits=[‘apple‘,‘orange‘,‘banana‘,‘grape‘]
for fruit in Fruits:
print(fruit)
print("结束遍历")

#for循环主要用来遍历、循环、序列、集合、字典
#把banana改为Apple
Fruits=[‘apple‘,‘orange‘,‘banana‘,‘grape‘]
for i in range(len(Fruits)):
if Fruits[i]==‘banana‘:
Fruits[i]=‘apple‘
print(Fruits)

Fruits=[‘apple‘,‘orange‘,‘banana‘,‘grape‘]
for i in Fruits:
if i==‘banana‘:
Fruits.remove(i)
print(Fruits)

#统计apple的个数
Fruits=[‘apple‘,‘orange‘,‘banana‘,‘grape‘,‘apple‘]
count=0
for i in Fruits:
if i==‘apple‘:
count+=1
print("Fruits列表中apple的个数="+str(count)+"个")

for str in ‘abc‘:
print(str)

for str in {‘a‘,2,‘bc‘}:
print(str)

for key,value in {"name":‘Kaina‘,"age":22}.items():
print("键---"+key)
print("值---"+str(value))