如何写出优雅的Python

mac2022-06-30 19

Looping over a range of numbers

Bad：

for i in [0,1,2,3,4,5]: print i**2

Good:

for i in range(6): print i**2

Looping over a collection:

Bad:

colors = [ 'red','green','blue','yellow'] for i in range(len(colors)): print colors[i]

Good:

for i in colors: print colors[i]

Looping backwards

Bad:

colors = ['red','green','blue','yellow'] for i in range(len(colors)-1,-1,-1): print colors(i)

Good:

colors = ['red','green','blue','yellow'] for color in reversed(colors): print color

Looping over a collection and indicies

Bad:

colors = ['red','green','blue','yellow'] for i in range(len(colors)): print i, '-->', colors[i]

Good:

colors = ['red','green','blue','yellow'] for i,color in enmerate(colors): print i, '-->', colors[i]

Looping over two collections

Bad:

names = ['raymond','rachel','mattew'] colors = ['red','green','blue','yellow'] n = min(len(names),len(colors)) for i in range(n): print names[i],'-->',colors[i]

Good:

names = ['raymond','rachel','mattew'] colors = ['red','green','blue','yellow'] for name,color in zip(names,colors): print name,'-->',color

Even beeter.(izip 依次处理，zip是全部读入后处理，如果在中间中断的话，izip不需要读入所有内容）

from itertools import izip names = ['raymond','rachel','mattew'] colors = ['red','green','blue','yellow'] for name,color in izip(names,colors): print name,'-->',color

转载于:https://www.cnblogs.com/db2zos/p/4660007.html