使用 df.loc 为数据帧设置值更新数据帧的副本

Question

import pandas as pd

#Inserting some data into name_df 

list_name = ["Al","Brad"]  
list_age = [20,30]

name_df = pd.DataFrame(list_name,columns=["name"])  
age_df = pd.DataFrame(list_age,columns=["age"])

name_df = pd.concat([name_df,age_df],axis=1)

**#Make a copy of the dataframe**  
copy_df = name_df  

**#Editing the data in name_df**  
name_df.loc[name_df["name"]=="Brad", ["age"]] = 35

**#Change appears in copy_df**  
print(copy_df)

这应该发生吗？

Answer 1

复制一份。 (copy.deepcopy())

import pandas as pd
import copy 
list_name = ["Al","Brad"]  
list_age = [20,30]

name_df = pd.DataFrame(list_name,columns=["name"])  
age_df = pd.DataFrame(list_age,columns=["age"])

name_df = pd.concat([name_df,age_df],axis=1)

copy_df = copy.deepcopy(name_df)  

name_df.loc[name_df["name"]=="Brad", ["age"]] = 35

print(copy_df)

使用 df.loc 为数据帧设置值更新数据帧的副本

Setting value to a dataframe using df.loc updates a copy of the dataframe

python

pandas

pandas-loc