matplotlib multiple lines for multiple years on same chart

Question

I am analyzing consumptions and want to build graphs which looks like this: E.g. Gas

• On the y axis there is the consupmtion in kWh
• On the x axis are the months (Jan-Dec)
• Each line represents a year

The data that I have looks like this (its quite fragmented for some years I have a lot of data points for some only one or two:

Datum	Art	Amount
06.03.2022	Wasser	1195
06.03.2022	Strom	8056
06.03.2022	Gas	27079,019
09.02.2022	Wasser	1187
09.02.2022	Strom	7641
09.02.2022	Gas	26845,138
10.01.2022	Strom	6897

You can download from here

My code looks like this:

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

from pathlib import Path

file_path_out_2021_2022 = "../data/raw_Consumption_data.xlsx"
df = pd.read_excel(file_path_out_2021_2022)

than some calculations

#rename columns
df = df.rename(columns={'Datum':'DATE', 'Art':'CATEGORY', 'Amount':'AMOUNT'})
#convert date
df['DATE'] = pd.to_datetime(df['DATE'], format = "%Y-%m-%d", dayfirst=True)

df['MONTH'] =  df['DATE'].dt.month
df['YEAR'] =  df['DATE'].dt.year

df_gas = df[(df['CATEGORY'] == "Gas")]
df_gas = df_gas.fillna(0)
df_gas['PREV_DATE'] = df_gas['DATE']
df_gas['PREV_DATE'] = df_gas.PREV_DATE.shift(-1)
df_gas['PREV_AMOUNT'] = df_gas['AMOUNT']
df_gas['PREV_AMOUNT'] = df_gas.PREV_AMOUNT.shift(-1)

df_gas['DIFF_AMOUNT'] = df_gas['AMOUNT'] - df_gas['PREV_AMOUNT'] 
df_gas['DIFF_DATE'] = df_gas['DATE'] - df_gas['PREV_DATE']

df_gas['DIFF_DAY'] = df_gas['DIFF_DATE'].dt.days

df_gas['CONSUM_PER_DAY'] = df_gas['DIFF_AMOUNT'] / df_gas['DIFF_DAY']

df_gas['CONSUM_PER_DAY_KWH'] = df_gas['CONSUM_PER_DAY'] * 10.3
df_gas['CONSUM_PER_MONTH_KWH'] = df_gas['CONSUM_PER_DAY_KWH'] * 30
df_gas['CONSUM_PER_YEAR_KWH'] = df_gas['CONSUM_PER_MONTH_KWH'] * 12

and than the chart:

import pandas as pd
from datetime import datetime, timedelta
from matplotlib import pyplot as plt
from matplotlib import dates as mpl_dates

plt.style.use('seaborn')

#drop all rows which have 0 in all columns
df_gas = df_gas.loc[(df_gas!=0).any(axis=1)]

df_gas.sort_values(by='DATE', ascending=False, inplace=True)

#print(df_gas)

dates = df_gas['DATE']
y = df_gas['AMOUNT']

plt.plot_date(dates, y, linestyle='solid')

plt.tight_layout()

plt.show()