Python用三种方式统计词频

三种方法：

①直接使用dict

②使用defaultdict

③使用Counter

ps:`int()`函数默认返回0

①dict

text = "I'm a hand some boy!"

frequency = {}

for word in text.split():
    if word not in frequency:
        frequency[word] = 1
    else:
        frequency[word] += 1

②defaultdict

import collections

frequency = collections.defaultdict(int)

text = "I'm a hand some boy!"

for word in text.split():
    frequency[word] += 1

③Counter

import collections

text = "I'm a hand some boy!"
frequency = collections.Counter(text.split())