python小技巧

同时遍历两个列表

nfc = ["Packers", "49ers"]
afc = ["Ravens", "Patriots"]
for i,j in zip(nfc,afc):
    print(i,j)

Packers Ravens
49ers Patriots

列表转换成字符串

teams = ["Packers", "49ers", "Ravens", "Patriots"]
print(','.join(teams))
type(','.join(teams))

 

Packers,49ers,Ravens,Patriots

str

遍历列表同时得出序号和内容

teams = ["Packers", "49ers", "Ravens", "Patriots"]
for index, team in enumerate(teams):
    print(index, team)

0 Packers
1 49ers
2 Ravens
3 Patriots

 

从字典中获得值

In [10]:

 

 

 

 

 

data = {'user': 1, 'name': 'Max', 'three': 4}

is_admin = data.get('admin', False)

print(is_admin)

 

 

 

False

 

Collections模块

 

  1 from collections import Counter

 2 print(Counter('hello')) 

 

Counter({'l': 2, 'h': 1, 'e': 1, 'o': 1})

 

Itertools模块

 

 

from itertools import combinations
  
teams = ["Packers", "49ers", "Ravens", "Patriots"]
for game in combinations(teams, 2):
    print(game)
  

('Packers', '49ers')
('Packers', 'Ravens')
('Packers', 'Patriots')
('49ers', 'Ravens')
('49ers', 'Patriots')
('Ravens', 'Patriots')