如何获取 apply function of pandas 中的所有 df 数据

Question

import pandas as pd
test_df =pd.DataFrame({"col1":[1,12,3,4],
            "col2":[3,14,5,6],
             "col3":[4,5,6,7]})

print(test_df)
   col1  col2  col3
0     1     3     4
1    12    14     5
2     3     5     6
3     4     6     7

def highlight(row):
    df1 = pd.DataFrame('', index=row.index, columns=row.columns)
    # set columns by condition
    df1.loc[row['col2'] == 5, 'col2'] = "AA"
    df1.loc[row['col3'] == 5, 'col3'] = "BB"
        
    return ret

df_output= test_df.apply(highlight, axis=1)

Error given above code: AttributeError: 'Series' object has no attribute 'columns' Request you please help me to correct highlight method code.

Answer 1

row inside you function will be a series . Apply with axis=1 sends to the function one row at time. What you are trying can be achieved without an apply.

test_df.loc[test_df.col2==5, 'col2'] = "AA"

Answer 2

def highlight(row):
    ret = [ i for i in row.values] 
    # set columns by condition
    if row['col2'] == 5:                                                                         
        ret[row.index.get_loc('col2')] ="AA" 
    if row['col3'] == 5:                                                                         
        ret[row.index.get_loc('col3')] ="BB" 
        
    return ret

data= test_df.apply(highlight, axis=1)
d= data.tolist()
s= pd.DataFrame(d, index=[1,2,3,4],columns=['col1','col2','col3'])