如何从另一列创建具有字典计数的熊猫列？

Question

我有一个示例数据：

date        product campaign_type             total_monthly_sale
2019-01-01. Dell      [call, email, call].       5
2019-01-01. Apple     [fax, fax, visit, visit]   4
2019-02-01. Dell      [call, fax, call]          6
2019-02-01. Apple     [email, email, visit]      7

我想创建一个名为 'campaign_dict' 的新列，它给出了来自 campaign_type 列的值的计数。

示例输出如下：

date        product campaign_type             total_monthly_sale. campaign_dict
2019-01-01. Dell      [call, email, call].       5.               {'call':2,'email':1} 
2019-01-01. Apple.    [fax, fax, visit, visit].  4.               {'fax':2,'visit':2}
2019-02-01. Dell.     [call, fax, call]          6.               {'call':2,'fax':1}
2019-02-01. Apple.    [email, email, visit].     7                {'email':2,'visit':1}

Answer 1

试试这样的

from collections import Counter

df["campaign_dict"] = df["campaign_type"].apply(Counter)

Answer 2

您需要的是collections.Counter

import pandas as pd
from collections import Counter

df: pd.DataFrame = pd.DataFrame([
    [["call", "email", "call"], 5],
    [["fax", "fax", "visit", "visit"], 4],
    [["call", "fax", "call"], 6],
    [["email", "email", "visit"], 7]
], columns=['campaign_type', 'total_monthly_sale'])

df['campaign_dict'] = df['campaign_type'].apply(Counter)
print(df) 

              campaign_type  total_monthly_sale             campaign_dict
0       [call, email, call]                   5   {'call': 2, 'email': 1}
1  [fax, fax, visit, visit]                   4    {'fax': 2, 'visit': 2}
2         [call, fax, call]                   6     {'call': 2, 'fax': 1}
3     [email, email, visit]                   7  {'email': 2, 'visit': 1}