在Python中使用defaultdict初始化字典以及应用方法

#!/usr/bin/python
 
from collectionsimport defaultdict
 
s = [(\'yellow\',1), (\'blue\', 2), (\'yellow\', 3), (\'blue\', 4), (\'red\', 1)]
d =defaultdict(list)
for k,v in s:
d[k].append(v)
print(d.items()

[(\'blue\', [2, 4]),(\'red\', [1]), (\'yellow\', [1, 3])]

from collectionsimport defaultdict
 
s = \'mississippi\'
d =defaultdict(int)
for k in s:
d[k] += 1
print(d.items())

E:\\WorkSpace\\05_数据分析\\01_利用Python进行数据分析\\第02章_引言>pythondict_int_int.py
[(\'i\', 4), (\'p\',2), (\'s\', 4), (\'m\', 1)]