Pandas Dataframe – replace NaN with 0 if column value condition

I have searched all around the internet and tried many methods before making this post, I have a dataframe where I want to:

• Replace NaN value of TGT_COLUMN_SCALE to 0 If TGT_COLUMN_DATA_TYPE is equals to NUMERIC.

Kindly help me out with this issue.

I tried this code but it’s not working:

df["TGT_COLUMN_SCALE"] = np.where(df["TGT_COLUMN_DATA_TYPE"] == "NUMERIC", 'NaN', 0)

>Solution :

Sample:

df = pd.DataFrame({
    "TGT_COLUMN_DATA_TYPE" : ["DATE", "NUMERIC", "STRING", "NUMERIC"],
    "TGT_COLUMN_SCALE" : [np.NaN, np.NaN, 4.0, 5.0]
})

Replace

df.loc[(df.TGT_COLUMN_DATA_TYPE == "NUMERIC") & (df.TGT_COLUMN_SCALE.isnull()), "TGT_COLUMN_SCALE"] = 0

Result:

    TGT_COLUMN_DATA_TYPE    TGT_COLUMN_SCALE
0   DATE    NaN
1   NUMERIC 0.0
2   STRING  4.0
3   NUMERIC 5.0