How to use df.replace(key:value) inside for loop in python-CodePudding

Below is the dummy data from my dataset

    Airline Source  Destination Route   Dep_Time    Duration    Total_Stops Additional_Info Month   Day Price
0   3   0   5   18  1.647042    1.647042    4   8   3   24  3897
1   1   3   0   84  -1.258929   -1.258929   1   8   1   5   7662
2   4   2   1   118 -0.606391   -0.606391   1   8   9   6   13882
3   3   3   0   91  0.924899    0.924899    0   8   12  5   6218
4   3   0   5   29  0.655184    0.655184    0   8   1   3   13302

Now I want replace the values of some of the columns with below dictionary using the for loop

airdic = {4: 36.02920528, 3: 19.21744828, 1: 16.39988767}

I'm using below code to replace the values but it's not working

Note: replace function is working outside the for loop

for i in cat_var_3:
    dummydf.replace({(i):airdic})

car_var_3 is the list containing the column names

How do I resolve it ?

CodePudding user response：

You will need to include inplace = True as the replace operation does not happen in place. Please refer below:

cat_var_3 = ['Ai','Dura']
airdic = {4: 36.02920528, 3: 19.21744828, 1: 16.39988767}
for i in cat_var_3:
    df.replace({(i):airdic},inplace=True)

print(df)

          Ai  rline  ...  tion  Total_Stops Additional_Info Month   Day Price
0  19.217448      0  ...    24                                           3897
1  16.399888      3  ...     5                                           7662
2  36.029205      2  ...     6                                          13882
3  19.217448      3  ...     5                                           6218
4  19.217448      0  ...     3                                          13302

CodePudding user response：

if cat_var3 is the list of column then you can simply execute the following code it'll traverse each column and map the desired dictionary

for i in cat_var_3:
    df[i] = df[i].map(airdic)