python - Apply an operation on the value of column B depending on the value of column A - Pandas

Question

I have the following dataset:

id  Wages   PayFreq
0   1013    Weekly
1   5000    Monthly
2   892     Weekly
3   2320    Bi-Weekly
4   1068    Weekly

I intend to perform the following operation:

if PayFreq == 'Monthly':
   (Wages / 4) * 52
elif PayFreq == 'Bi-Weekly':
   (Wages / 2) * 52
else:
    Wages * 52

I need to select the operation to apply to the wages column based on what is present in the PayFreq column. Any ideas ?

Answer 1

I would sugest to use Dataframe's apply as it is very simple and intuitive.

You can define a method you want to apply on the dataframe, you can choose either Lambda expression or explicit function for that. For example, here is a simple implementation with a function:

def func(row):
    if row['PayFreq'] == 'Monthly':
        return (row['Wages'] / 4) * 52
    elif row['PayFreq'] == 'Bi-Weekly':
        return (row['Wages'] / 2) * 52
    else:
        return row['Wages'] * 52

And in order to apply it on your dataframe (on the right axis):

df['NewWages'] = df.apply(func, axis=1)

The result:

   Wages    PayFreq  NewWages
0   1013     Weekly   52676.0
1   5000    Monthly   65000.0
2    892     Weekly   46384.0
3   2320  Bi-Weekly   60320.0
4   1068     Weekly   55536.0