lis = [11, 22, 33, 44, 55]

for i in range(len(lis)):

    print(i)

    del lis[i]

    print(lis)    # 由于列表元素被删除，造成索引改变，循环到后面根据索引将找不到元素

# fromkeys  将元素分别对应前面的键

dic = dict.fromkeys([1, 2, 3], 'zxc')

print(dic)    # {1: 'zxc', 2: 'zxc', 3: 'zxc'}

# 如果后面是可迭代的元素，前面的键将共用这一个元素

dic = dict.fromkeys([1, 2, 3], [])

print(dic)     # {1: [], 2: [], 3: []}

dic[1].append('zxc')   # 修改一个，都发生变化

print(dic)    # {1: ['zxc'], 2: ['zxc'], 3: ['zxc']}

li = ['zxc', 'zxf', 'zxv']

for i, j in enumerate(li, 1):

    print(i, j)

tu = (1)

tu1 = (1,)

print(type(tu), type(tu1))    # <class 'int'> <class 'tuple'>

tu = ([1])

tu1 = ([1],)

print(type(tu), type(tu1))    # <class 'list'> <class 'tuple'>