import pandas as pd
import altair as alt
import numpy as np
spending = pd.read_csv('./personal_transactions.csv')
spending
df_month_year = spending.copy()
df_month_year['Date'] = pd.to_datetime(df_month_year['Date'])
df_month_year['month'] = df_month_year.Date.dt.month
df_month_year['year'] = df_month_year.Date.dt.year
df_month_year=df_month_year[df_month_year['year'].isin([2018, 2019])]
df_month_year=df_month_year.groupby(['year','month']).sum()['Amount'].reset_index()
df_month_year
alt.Chart(df_month_year).mark_circle().encode(
y='Amount',
x='month',
color='year:N'
)