#切片
L = [‘Michael‘, ‘Sarah‘, ‘Tracy‘, ‘Bob‘, ‘Jack‘]
print(L[0:3])
print(L[:3])
print(L[1:3])
print(L[:10:2])
print(L[::5])
print(L[:]) #复制一个list

print((0, 1, 2, 3, 4, 5)[:3])

print(‘ABCDEFG‘[:3])

from collections import Iterable

d = {‘a‘: 1, ‘b‘: 2, ‘c‘: 3}

for key in d:
    print(key)

for value in d.values():
    print(value)

for k, v in d.items():
    print(k, v)


for ch in ‘ABC‘:
    print(ch)

# 是否可迭代
print(isinstance(123, Iterable))

#Python内置的enumerate函数可以把一个list变成索引-元素对，这样就可以在for循环中同时迭代索引和元素本身
for i, value in enumerate([‘A‘, ‘B‘, ‘C‘]):
    print(i, value)

for x, y in [(1, 1), (2, 4), (3, 9)]:
    print(x, y)

print(list(range(1, 11)))

L = []
for v in list(range(1, 11)):
    L.append(v * v)
print(L)

#写列表生成式时，把要生成的元素x * x放到前面，后面跟for循环，就可以把list创建出来
print([x * x for x in range(1, 11)])

print([x * x for x in range(1, 11) if x % 2 == 0])

print([m + n for m in ‘ABC‘ for n in ‘XYZ‘])

d = {‘x‘: ‘A‘, ‘y‘: ‘B‘, ‘z‘: ‘C‘ }
print([k + ‘=‘ + v for k, v in d.items()])

L = [‘Hello‘, ‘World‘, ‘IBM‘, ‘Apple‘]
print([s.lower() for s in L])