def datetime_range(start, end, delta):
current = start
while current < end:
    yield current
    current += delta

import pandas as pd
import numpy as np
import cProfile
from datetime import timedelta, date, datetime

#inputs
empty_data = pd.DataFrame(columns=['store','timestamp'])
start_dt = date(2019, 1, 1)
days = 365

data = "input data | attached to the post"
for i in range(days):
for j in range(len(data.store)):
curr_date = start_dt + timedelta(days=i)
curr_date_year = curr_date.year
curr_date_month = curr_date.month
curr_date_day =  curr_date.day
weekno = curr_date.weekday()
if weekno<5:
  dts = [dt.strftime('%Y-%m-%d %H:%M') for dt in
  datetime_range(datetime(curr_date_year,curr_date_month,curr_date_day,data['m_f_open_hrs'].iloc[j],data['m_f_open_min'].iloc[j]), datetime(curr_date_year,curr_date_month,curr_date_day, data['m_f_close_hrs'].iloc[j],data['m_f_close_min'].iloc[j]),
  timedelta(minutes=15))]
  vert = pd.DataFrame(dts,columns = ['timestamp'])
  vert['store']= data['store'].iloc[j]
  empty_data = pd.concat([vert, empty_data])
elif weekno==5:
  dts = [dt.strftime('%Y-%m-%d %H:%M') for dt in
  datetime_range(datetime(curr_date_year,curr_date_month,curr_date_day,data['sat_open_hrs'].iloc[j],data['sat_open_min'].iloc[j]), datetime(curr_date_year,curr_date_month,curr_date_day, data['sat_close_hrs'].iloc[j],data['sat_close_min'].iloc[j]),
  timedelta(minutes=15))]
  vert = pd.DataFrame(dts,columns = ['timestamp'])
  vert['store']= data['store'].iloc[j]
  empty_data = pd.concat([vert, empty_data])
else:
  dts = [dt.strftime('%Y-%m-%d %H:%M') for dt in
  datetime_range(datetime(curr_date_year,curr_date_month,curr_date_day,data['sun_open_hrs'].iloc[j],data['sun_open_min'].iloc[j]), datetime(curr_date_year,curr_date_month,curr_date_day, data['sun_close_hrs'].iloc[j],data['sun_close_min'].iloc[j]),
  timedelta(minutes=15))]
  vert = pd.DataFrame(dts,columns = ['timestamp'])
  vert['store']= data['store'].iloc[j]
  empty_data = pd.concat([vert, empty_data])


final_data = empty_data