计算特定行值出现的频率＆amp;在Python中输出组合

Question

我有一个CSV，其中包含我想要迭代的销售数据，以列出同一买家经常购买的类别。我想我可以用字典和a script like this来做到这一点但是我无法概念化如何计算同一买家在不同类别中出现的次数。

CSV数据样本：

buyer_id | order_id | category
1, 10, shoes
1, 11, outerwear
2, 12, beauty
2, 13, shoes
2, 14, outerwear

在那个样本中，我想知道鞋子，外套至少是两次组合。

Answer 1

import pandas as pd
#Creating dataframe
data = pd.DataFrame(
    {'Buyer_ID': [1,1,2,2,2,1],
     'Order_ID': [10,11,12,13,14,15],
     'Category':['shoes','outerwear','beauty','shoes','outerwear','shoes']
    })

data
Out[]: 
   Buyer_ID   Category  Order_ID
0         1      shoes        10
1         1  outerwear        11
2         2     beauty        12
3         2      shoes        13
4         2  outerwear        14
5         1      shoes        15

# Output: Same buyer and unique categories
data.groupby(["Buyer_ID", "Category"]).size()

# Buyer_ID:1 with two shoes entry is displayed only once (hence only unique categories are considered). 
Out[]: 
Buyer_ID  Category 
1         outerwear    1
          shoes        2
2         beauty       1
          outerwear    1
          shoes        1
dtype: int64