Evaluate these two files:
from html.parser import HTMLParser
import urllib.request
from datetime import datetime, timedelta
import logging
from dateutil.parser import parse

class WeatherScraper(HTMLParser):
    """A parser for extracting temperature values from a website."""

    logger = logging.getLogger("main." + __name__)

    def __init__(self):
        try:
            super().__init__()
            self.is_tbody = False
            self.is_td = False
            self.is_tr = False
            self.last_page = False
            self.counter = 0
            self.daily_temps = {}
            self.weather = {}
            self.row_date = ""
        except Exception as e:
            self.logger.error("scrape:init:%s", e)

    def is_valid_date(self, date_str):
        """Check if a given string is a valid date."""

        try:
            parse(date_str, default=datetime(1900, 1, 1))
            return True
        except ValueError:
            return False

    def is_numeric(self, temp_str):
        """Check if given temperature string can be converted to a float."""

        try:
            float(temp_str)
            return True
        except ValueError:
            return False

    def handle_starttag(self, tag, attrs):
        """Handle the opening tags."""

        try:
            if tag == "tbody":
                self.is_tbody = True
            if tag == "tr" and self.is_tbody:
                self.is_tr = True
            if tag == "td" and self.is_tr:
                self.counter += 1
                self.is_td = True
            if tag == "abbr" and self.is_tr and self.is_valid_date(attrs[0][1]): # Only parses the valid dates, all other values are excluded.
                self.row_date = str(datetime.strptime(attrs[0][1], "%B %d, %Y").date())
                
            if len(attrs) == 2:
                if attrs[1][1] == "previous disabled":
                     self.last_page = True
        except Exception as e:
            self.logger.error("scrape:starttag:%s", e)

    def handle_endtag(self, tag):
        """Handle the closing tags."""

        try:
            if tag == "td":
                self.is_td = False
            if tag == "tr":
                self.counter = 0
                self.is_tr = False
        except Exception as e:
            self.logger.error("scrape:end:%s", e)

    def handle_data(self, data):
        """Handle the data inside the tags."""
        
        try:
            if self.is_tbody and self.is_td and self.counter <= 3 and data.strip():
                if self.counter == 1 and self.is_numeric(data.strip()):
                    self.daily_temps["Max"] = float(data.strip())
                if self.counter == 2 and self.is_numeric(data.strip()):
                    self.daily_temps["Min"] = float(data.strip())
                if self.counter == 3 and self.is_numeric(data.strip()):
                    self.daily_temps["Mean"] = float(data.strip())
                    self.weather[self.row_date] = self.daily_temps
                    self.daily_temps = {}
        except Exception as e:
            self.logger.error("scrape:data:%s", e)

    def get_data(self):
        """Fetch the weather data and return it as a dictionary of dictionaries."""

        current_date = datetime.now()

        while not self.last_page:
            try:
                url = f"https://climate.weather.gc.ca/climate_data/daily_data_e.html?StationID=27174&timeframe=2&StartYear=1840&EndYear=2018&Day={current_date.day}&Year={current_date.year}&Month={current_date.month}"

                with urllib.request.urlopen(url) as response:
                    html = response.read().decode()
                self.feed(html)

                current_date -= timedelta(days=1) # Subtracts one day from the current date and assigns the resulting date back to the current_date variable.
            except Exception as e:
                self.logger.error("scrape:get_data:%s", e)

        return self.weather

# Test program.
if __name__ == "__main__":
    print_data = WeatherScraper().get_data()
    for k, v in print_data.items():
        print(k, v)

import sqlite3
import logging
from scrape_weather import WeatherScraper


class DBOperations:
    """Class for performing operations on a SQLite database"""

    def __init__(self, dbname):
        """
        Constructor for DBOperations class.

        Parameters:
        - dbname: str, the name of the SQLite database file to use
        """
        self.dbname = dbname
        self.logger = logging.getLogger(__name__)

    def initialize_db(self):
        """
        Initialize the SQLite database by creating the weather_data table.

        This method should be called every time the program runs.
        """
        with self.get_cursor() as cursor:
            try:
                cursor.execute('''
                    CREATE TABLE IF NOT EXISTS weather_data (
                        id INTEGER PRIMARY KEY AUTOINCREMENT,
                        sample_date TEXT UNIQUE,
                        location TEXT UNIQUE,
                        min_temp REAL,
                        max_temp REAL,
                        avg_temp REAL
                    )
                ''')
                self.logger.info("Initialized database successfully.")
            except sqlite3.Error as e:
                self.logger.error(f"An error occurred while creating the table: {e}")

    def save_data(self, data):
        """
        Save weather data to the SQLite database.

        If the data already exists in the database, it will not be duplicated.

        Parameters:
        - data: dict, the weather data to save to the database. Must have keys for
          sample_date, location, min_temp, max_temp, and avg_temp.
        """
        with self.get_cursor() as cursor:
            try:
                cursor.execute('''
                    INSERT OR IGNORE INTO weather_data
                    (sample_date, location, min_temp, max_temp, avg_temp)
                    VALUES (?, ?, ?, ?, ?)
                ''', (data['sample_date'], data['location'], data['min_temp'], data['max_temp'], data['avg_temp']))
                self.logger.info("Data saved successfully.")
            except sqlite3.Error as e:
                self.logger.error(f"An error occurred while saving data to the database: {e}")

    def fetch_data(self, location):
        """
        Fetch weather data from the SQLite database for a specified location.

        Parameters:
        - location: str, the location to fetch weather data for

        Returns:
        - A list of tuples containing the weather data for the specified location,
          where each tuple has the format (sample_date, min_temp, max_temp, avg_temp).
          Returns an empty list if no data is found for the specified location.
        """
        with self.get_cursor() as cursor:
            try:
                cursor.execute('''
                    SELECT sample_date, min_temp, max_temp, avg_temp
                    FROM weather_data
                    WHERE location = ?
                ''', (location,))
                data = cursor.fetchall()
                self.logger.info("Data fetched successfully.")
                return data
            except sqlite3.Error as e:
                self.logger.error(f"An error occurred while fetching data from the database: {e}")
                return []

    def purge_data(self):
        """
        Purge all weather data from the SQLite database.
        """
        with self.get_cursor() as cursor:
            try:
                cursor.execute('DELETE FROM weather_data')
                self.logger.info("Data purged successfully.")
            except sqlite3.Error as e:
                self.logger.error(f"An error occurred while purging data from the database: {e}")

    def get_cursor(self):
        """
        Get a cursor to use for database operations.

        Returns:
        - A cursor object for the SQLite database.
        """
        return DBCM(self.dbname)


class DBCM:
    def __init__(self, dbname):
        self.dbname = dbname
        self.logger = logging.getLogger(__name__)

    def __enter__(self):
        try:
            self.conn = sqlite3.connect(self.dbname)
            self.cursor = self.conn.cursor()
            self.logger.info("Connection to database established successfully.")
            return self.cursor
        except sqlite3.Error as e:
            self.logger.error(f"An error occurred while connecting to the database: {e}")
            return None

    def __exit__(self, exc_type, exc_val, exc_tb):
        if exc_type is not None:
            self.conn.rollback()
        else:
            try:
                self.conn.commit()
                self.logger.info("Changes committed successfully.")
            except sqlite3.Error as e:
                self.logger.error(f"An error occurred while committing changes to the database: {e}")
        try:
            self.cursor.close()
            self.conn.close()
            self.logger.info("Connection to database closed successfully.")
        except sqlite3.Error as e:
            self.logger.error(f"An error occurred while closing the database connection: {e}")


def main():
    # Initialize the database
    db = DBOperations("mydatabase.db")
    db.initialize_db()

    # Get the weather data
    scraper = WeatherScraper()
    data = scraper.get_data()

    # Process the data and prepare the rows
    rows = []
    for date, temps in data.items():
        row = (
            date,
            "Winnipeg",
            temps["Max"],
            temps["Min"],
            temps["Mean"]
        )
        rows.append(row)

    # Save the data to the database
    with db.get_cursor() as cursor:
        try:
            cursor.executemany('''
                INSERT OR IGNORE INTO weather_data
                (sample_date, location, min_temp, max_temp, avg_temp)
                VALUES (?, ?, ?, ?, ?)
            ''', rows)
            db.logger.info(f"Inserted {len(rows)} rows into the database.")
        except sqlite3.Error as e:
            db.logger.error(f"An error occurred while inserting data: {e}")

if __name__ == '__main__':
    main()