How to replace NaN values in Pandas conditionally?

Question

I\'m using famous Titanic dataset for my first Kaggle problem. I\'m getting stuck in dataset. I want to replace NaN values of Age gender wise e.g. missing values for \'male\' sh

Answer 1

import pandas as pd
import numpy as np

df = pd.read_csv('train.csv')
df['Age'].fillna(df.groupby(["Sex"])["Age"].transform(np.mean), inplace=True)

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Maybe this was something you were trying to do? I didn't get any warning though. Have a look at my blog post too if necessary.