Set column value as the mean of a group in pandas
df['my_label_mean_temperature']= df.groupby('label', as_index=False)['temperature'].mean()
I have a data frame with columns X Y temperature Label
label is an integer between 1 and 9 
I want to add an additional column my_label_mean_temperature which will contain for each row the mean of the temperatures of the rows that has the same label.
I'm pretty sure i need to start with my_df.groupby('label') but not sure how to calculate the mean on temperature and propagate the values on all the rows of my original data frame