pandas 列中列表中元素的值计数

Question

我有一列包含大小不一但项目数量有限的列表。

print(df['channels'].value_counts(), '\n')

输出：

[web, email, mobile, social]    77733
[web, email, mobile]            43730
[email, mobile, social]         32367
[web, email]                    13751

所以我想要网络、电子邮件、移动和社交的总次数。

这些应该是：

web =    77733 + 43730 + 13751            135,214
email =  77733 + 43730 + 13751 + 32367    167,581
mobile = 77733 + 43730 + 32367            153,830
social = 77733 + 32367                    110,100

我试过以下两种方法：

sum_channels_items = pd.Series([x for item in df['channels'] for x in item]).value_counts()
print(sum_channels_items)

from itertools import chain
test = pd.Series(list(chain.from_iterable(df['channels']))).value_counts()
print(test)

两者都因相同的错误而失败（仅显示第二个）。

Traceback (most recent call last):
  File "C:/Users/Mark/PycharmProjects/main/main.py", line 416, in <module>
    test = pd.Series(list(chain.from_iterable(df['channels']))).value_counts()
TypeError: 'float' object is not iterable

Answer 1

一个选项是explode，然后计数值：

out = df['channels'].explode().value_counts()

另一个可能是使用 collections.Counter。请注意，您的错误表明您在该列中缺少值，因此您可以先删除它们：

from itertools import chain
from collections import Counter
out = pd.Series(Counter(chain.from_iterable(df['channels'].dropna())))

pandas 列中列表中元素的值计数

pandas value count of elements in list in column

python-3.x

pandas

list-comprehension

itertools