数据类型的循环与取值--小结

一、列表

names=["Ezreal","Caitlyn","Vayne","Zed"]

1.不按照索引取值
for name in names:
    print(name,end=" ")    # Ezreal Caitlyn Vayne Zed

2.按照索引取值

2.1 for循环
for name in range(len(names)):
    print(name,names[name])
2.2while 循环
count=0
while count<len(names):
    print(count,names[count])
    count+=1

二、元组

names=（"Ezreal","Caitlyn","Vayne","Zed"）
1.不按照索引取值
for name in names:
    print(name)     

2.按照索引取值
for name in range(len(names)):
    print(name,names[name])

三、字典

lol={"name":"Ezreal","position":"ADC","opponent":"Vayne"}
1.只取key
1.1 通常情况
for item in lol:
    print(item)           #name    position    opponent
1.2  专门玩法
for k in lol.keys():
    print(i)                #name     position    opponent
2. 只取value
for v in lol.values():
    print(v)               #Ezreal      ADC      Vayne
3. 取出key和value
3.1 通常情况
for item in lol:
    print(item,lol[item])
3.2 专门玩法
for k,v in lol.items():
    print(k,v)

四、字符串

字符串的循环会将字符串中的所有元素依次取出，生成新的字符串

str="abcde"
for i in str:
    print(i,type(i))

#a <class 'str'>
#b <class 'str'>
#c <class 'str'>
#d <class 'str'>
#e <class 'str'>