Python中的可迭代对象

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  Python中的可迭代对象有：列表、元组、字典、字符串；常结合for循环使用；

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判断一个对象是不是可迭代对象:

from collections import Iterable

isinstance(list(range(100)), Iterable)
isinstance('Say YOLO Again.')

列表:

L = list(range(100))
for i in L:
    print(i)

元组:

T = tuple(range(100))
for i in T:
    print(i)

字典:

dic = {'name': 'chen', 'age': 25, 'loc': 'Tianjin'}

# 以列表的形式返回key
list(dic.keys())

# 以列表的形式返回value
list(dic.values())

# 循环key
for key in dic:
    print(key)
    
# 循环value
for value in dic.values():
    print(value)
    
# 循环key, value
for key, value in dic.items():
    print(key, value)

字符串:

S = 'Say YOLO Again!'
for s in S:
    print(s)

返回'索引-元素'对:

for i, value in enumerate('Say YOLO Again.'):
    print(i, value)