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Trouble with Python 3.8 and Pandas GroupBy returning unexpected NaN values

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python pandas dataframe Python

I'm currently using Python 3.8 with Pandas for data manipulation, and I've run into an scenario when trying to group data and calculate the mean. I have a DataFrame containing sales data with columns for 'Region', 'Sales', and 'Profit'. When I apply the `groupby` function and calculate the mean on 'Profit', I'm getting unexpected NaN values in the result, which doesn't seem right based on my data. Here’s the code I'm using: ```python import pandas as pd # Sample data data = { 'Region': ['East', 'West', 'East', 'West', 'East'], 'Sales': [250, 150, 300, 200, 100], 'Profit': [50, 30, None, 20, 10] } df = pd.DataFrame(data) # Grouping by 'Region' and calculating mean of 'Profit' result = df.groupby('Region', as_index=False)['Profit'].mean() print(result) ``` I expected to see the mean profit for each region without any NaN values, but instead I get: ``` Region Profit 0 East 30.0 1 West 25.0 ``` Why is the mean returning NaN for some groups, and how can I handle this situation properly? I've tried using `dropna()` before the `groupby`, but it didn't resolve the scenario. Any advice would be appreciated!