求助排查AttributeError：DataFrame对象无'Genre'属性问题

错误信息 #

Traceback (most recent call last):
  File "/Users/anishchowdary/Couch to Coder/Week 4/using_pandas.py", line 10, in <module>
    print(number_of_books_written.Genre)
  File "/Users/anishchowdary/PycharmProjects/ISAconverter/venv/lib/python3.9/site-packages/pandas/core/generic.py", line 6202, in __getattr__
    return object.__getattribute__(self, name)
AttributeError: 'DataFrame' object has no attribute 'Genre'

问题成因 #

执行sellers.groupby('Genre')[['Name']].count()时，Genre会被自动设为DataFrame的索引，而非普通列。此时number_of_books_written里不存在名为Genre的列，自然无法通过.Genre的方式访问。

解决办法 #

有两种常用修复方式：

方式1：分组时保留Genre为列 #

在groupby中添加as_index=False参数，让分组键保持为列而非索引：

import pandas as pd
import matplotlib.pyplot as plt

bestsellers = pd.read_csv("bestsellers with categories.csv")
sellers = bestsellers.drop_duplicates(subset='Name', keep='last')

# 添加as_index=False，Genre会作为普通列存在
number_of_books_written = sellers.groupby('Genre', as_index=False)[['Name']].count().sort_values("Name", ascending=False).head(10)

print(number_of_books_written.Genre)

方式2：将索引转回列 #

如果已生成目标DataFrame，可通过reset_index()把索引转换为列：

import pandas as pd
import matplotlib.pyplot as plt

bestsellers = pd.read_csv("bestsellers with categories.csv")
sellers = bestsellers.drop_duplicates(subset='Name', keep='last')

number_of_books_written = sellers.groupby('Genre')[['Name']].count().sort_values("Name", ascending=False).head(10)

# 重置索引，把Genre转回列
number_of_books_written = number_of_books_written.reset_index()
print(number_of_books_written.Genre)

额外说明：直接访问索引 #

若仅需查看Genre的取值，也可直接访问DataFrame的索引：

print(number_of_books_written.index)

内容的提问来源于stack exchange，提问作者twoinchpeepee