g1_m_retention.py

#identify which users are active by looking at their revenue per month
tx_user_purchase = tx_uk.groupby(['CustomerID','InvoiceYearMonth'])['Revenue'].sum().reset_index()

#create retention matrix with crosstab
tx_retention = pd.crosstab(tx_user_purchase['CustomerID'], tx_user_purchase['InvoiceYearMonth']).reset_index()

tx_retention.head()

#create an array of dictionary which keeps Retained & Total User count for each month
months = tx_retention.columns[2:]
retention_array = []
for i in range(len(months)-1):
    retention_data = {}
    selected_month = months[i+1]
    prev_month = months[i]
    retention_data['InvoiceYearMonth'] = int(selected_month)
    retention_data['TotalUserCount'] = tx_retention[selected_month].sum()
    retention_data['RetainedUserCount'] = tx_retention[(tx_retention[selected_month]>0) & (tx_retention[prev_month]>0)][selected_month].sum()
    retention_array.append(retention_data)
    
#convert the array to dataframe and calculate Retention Rate
tx_retention = pd.DataFrame(retention_array)
tx_retention['RetentionRate'] = tx_retention['RetainedUserCount']/tx_retention['TotalUserCount']

#plot the retention rate graph
plot_data = [
    go.Scatter(
        x=tx_retention.query("InvoiceYearMonth<201112")['InvoiceYearMonth'],
        y=tx_retention.query("InvoiceYearMonth<201112")['RetentionRate'],
        name="organic"
    )
    
]

plot_layout = go.Layout(
        xaxis={"type": "category"},
        title='Monthly Retention Rate'
    )
fig = go.Figure(data=plot_data, layout=plot_layout)
pyoff.iplot(fig)