preprocessing.py

import re
import pandas as pd

def preprocess(data):
    pattern = '\d{1,2}\/\d{1,2}\/\d{2,4},\s\d{1,2}:\d{1,2}\s(?:AM|PM|am|pm)\s-\s'
    messages = re.split(pattern, data)[1:]
    dates = re.findall(pattern, data)
    df = pd.DataFrame({'user_message': messages, 'message_date': dates})
    df['message_date'] = pd.to_datetime(df['message_date'], format="%d/%m/%y, %I:%M %p - ")
    df.rename(columns={'message_date': 'date'}, inplace=True)

    users = []
    messages = []
    for message in df['user_message']:
        entry = re.split('([\w\W]+?):\s', message)
        if entry[1:]:
            users.append(entry[1])
            messages.append(entry[2])
        else:
            users.append('group_notification')
            messages.append(entry[0])

    df['user'] = users
    df['message'] = messages
    df.drop(columns = ['user_message'], inplace=True)


    df['day_name'] = df['date'].dt.day_name()
    df['only_date'] = df['date'].dt.date
    df['year']=df['date'].dt.year
    df['month_num']= df['date'].dt.month
    df['month']= df['date'].dt.month_name()
    df['day'] = df['date'].dt.day
    df['hour'] = df['date'].dt.hour
    df['minute'] = df['date'].dt.minute

    period = []
    for hour in df[['day_name', 'hour']]['hour']:
        if hour == 23: period.append(str(hour) + '-' + str('00'))
        elif hour == 0: period.append(str('00') + '-' + str(hour+1))
        else: period.append(str(hour) + '-' + str(hour+1))

    df['period'] = period

    return df