g1_monthly_revenue.py

#converting the type of Invoice Date Field from string to datetime.
tx_data['InvoiceDate'] = pd.to_datetime(tx_data['InvoiceDate'])

#creating YearMonth field for the ease of reporting and visualization
tx_data['InvoiceYearMonth'] = tx_data['InvoiceDate'].map(lambda date: 100*date.year + date.month)

#calculate Revenue for each row and create a new dataframe with YearMonth - Revenue columns
tx_data['Revenue'] = tx_data['UnitPrice'] * tx_data['Quantity']
tx_revenue = tx_data.groupby(['InvoiceYearMonth'])['Revenue'].sum().reset_index()
tx_revenue