Pandas: filling missing values by mean in each group

Question

This should be straightforward, but the closest thing I\'ve found is this post: pandas: Filling missing values within a group, and I still can\'t solve my problem....

<

Answer 1

def groupMeanValue(group):
    group['value'] = group['value'].fillna(group['value'].mean())
    return group

dft = df.groupby("name").transform(groupMeanValue)