Pandas loc 为相同的过滤器提供不同的值

Question

我的数据框中类似过滤器的行数不同，我不知道为什么。这是我的代码 -

import numpy as np
import pandas as pd
df = pd.read_csv("Automobile_price_data_clean-f18.csv")
df
df.loc[(df['body-style']== 'hatchback') & df['city-mpg']]
a = df.loc[(df['body-style']== 'hatchback') & df['city-mpg']]
foo_1 = a.count()
b = df.loc[(df['body-style']== 'hatchback')]
foo_2 = b.count()
foo_1 == foo_2

这是我的数据 - https://paste.pythondiscord.com/apizixigay.apache

Answer 1

当然查询是不一样的。

  a = df.loc[(df['body-style']== 'hatchback') & df['city-mpg']]# incorporates city-mpg and hence restrictive. To check further try;

a.shape 与 b.shape

和

a['city-mpg'].nunique() 与 b['city-mpg'].nunique()