20170419数据结构的推导式/列表解析式

1.普通写法：

a = []
for i in range(1,10):
    a.append(i)
    print(a)
print(a)
2.列表解析式：

b = [i for i in range(1,10)]
print(b)
a = [i**2 for i in range(1,10)]
c = [j+1 for j in range(1,10)]
k = [n for n in range(1,100) if n % 2 == 0]
z = [letter.lower() for letter in 'ABCDEFGHIJKLMN']
print(a,'
',c,'
',k,'
',z)

3.字典推导式：

d = {i:i+1 for i in range(4)}
g = {i:j for i,j in zip(range(1,6),'abcde')}
h = {i:j.upper() for i,j in zip(range(1,6),'abcde')}
print(d,'
',g,'
',h)

字典必须满足键-值两个条件

4.循环列表索引

#循环列表索引
letters = ['a','b','c','d','e','f','g']
for num,letter in enumerate(letters):
    print(letter,' is ',num + 1)