如何在python中从数据帧列中删除分类值？

Question

我正在使用数据帧标题price_df。我想从drive-wheels列中删除包含'4wd'的行。在阅读了pandas中的docs页面后，我尝试了price_df2 = price_df.drop(index='4wd', axis=0)和其他一些变体，但仍然会得到错误代码。有人能告诉我从列和数据框中删除包含值4wd的行的正确方法吗？以下是我在尝试删除值之前运行的代码：

# Cleaned up Dataset location
fileName = "https://library.startlearninglabs.uw.edu/DATASCI410/Datasets/Automobile%20price%20data%20_Raw_.csv"
# Import libraries
from scipy.stats import norm
import numpy as np
import pandas as pd
import math
import numpy.random as nr
price_df = pd.read_csv(fileName)
round(price_df.head(),2) #getting an overview of that data
price_df.loc[:,'drive-wheels'].value_counts()
price_df2 = price_df.drop(index='4wd', axis=0)

Answer 1

使用以下一行代码获取数据的子集：

price_df2 = price_df[price_df.drive-wheels != '4wd']

Answer 2

试试这个

price_df = pd.read_csv(fileName)
mask = price_df["drive-wheels"] =="4wd"
price_df = price_df[~mask]

Answer 3

您可以使用pd.DataFrame.query和带连字符的倒勾来表示此列名：

price_df.query('`drive-wheels` != "4wd"')