如何在熊猫中将两列转换为正式列?

Question

我正在制作一个计算旧金山每个街区犯罪总数的项目，我使用了以下代码，但是当我尝试使用 crime_counts.dtypes 验证它时，它无法将邻里列识别为列

import pandas as pd 
file_name='https://cocl.us/sanfran_crime_dataset'
df=pd.read_csv(file_name)
crime_count = df["PdDistrict"].value_counts().to_frame('C').rename_axis('Neighbourhood')
crime_count = crime_count.rename(columns = {"PdDistrict":"Neighbourhood"})
crime_count = crime_count.rename(columns = {"C":"Counts"})
crime_count

我想创建一个数据帧，它将邻域和计数都识别为列。

Answer 1

首先通过 rename_axis 更改索引名称，然后将Series转换为 2 列，DataFrame Series.reset_index 参数 name ：

crime_count = (df["PdDistrict"].value_counts()
                               .rename_axis('Neighbourhood')
                               .reset_index(name='Counts'))
print (crime_count)
  Neighbourhood  Counts
0      SOUTHERN   28445
1      NORTHERN   20100
2       MISSION   19503
3       CENTRAL   17666
4       BAYVIEW   14303
5     INGLESIDE   11594
6       TARAVAL   11325
7    TENDERLOIN    9942
8      RICHMOND    8922
9          PARK    8699