calendar.py

#%%
import pandas as pd
df = pd.read_csv('https://www.city.yokohama.lg.jp/city-info/koho-kocho/koho/topics/corona-data.files/141003_yokohama_covid19_patients.csv', encoding='UTF-8')

#%%
import datetime
weeks = [0] * 8
output = []
dates = pd.to_datetime(df['公表日'])

start = dates[0]
stop = dates.iloc[-1]
# 月曜スタートにしたい
start -= datetime.timedelta(days=start.weekday())
weeks[0] = start

for n in range((stop - start).days + 1):
    date = start + datetime.timedelta(days = n)
    weekday = date.weekday()
    if weekday == 0:
        output.append(weeks)
        weeks = [0] * 8
        weeks[0] = date
    
    count = (dates == date).sum()
    weeks[weekday + 1] = count

if stop.weekday() != 6:
    output.append(weeks)

#%%
weekstr = ['', '月', '火', '水', '木', '金', '土', '日']
o2 = pd.DataFrame(output, columns = weekstr)
o2.to_csv('calendar.csv', encoding='Shift_JIS')