ipp4_0_single_anagrams

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Filename: ipp4_0_single_anagrams.py
# Version: 1.0.0
# Author: Jeoi Reqi

"""
Description:
    - This script demonstrates "Chapter 3: Project #4 - Single Anagrams" from the book "Impractical Python Projects" by Lee Vaughan.
    - This script allows users to find single word anagrams of a given word by searching a dictionary file.
    - It downloads a dictionary file from a specified URL, loads it into memory, and then searches for anagrams of the user-provided word within the dictionary.

Requirements:
    - Python 3.x
    - The following modules:
        - sys
        - requests

Functions:
    - download_dictionary(url, file_name):
        - Description:
            - Downloads a dictionary file from a URL.
        - Parameters:
            - url (str): The URL from which to download the dictionary file.
            - file_name (str): The name to save the downloaded file as.
        - Raises:
            - requests.RequestException: If an error occurs during the HTTP request.

    - load_dictionary(file):
        - Description:
            - Opens a text file and turns its contents into a list of lowercase strings.
        - Parameters:
            - file (str): The name of the file to open.
        - Returns:
            - list: A list of lowercase strings containing the words from the file.

    - find_anagrams(word, word_list):
        - Description:
            - Finds anagrams of a given word in a list of words.
        - Parameters:
            - word (str): The word to find anagrams for.
            - word_list (list): A list of words to search for anagrams.
        - Returns:
            - list: A list of anagrams found in the word list.

Usage:
    - Ensure you have Python 3.x installed on your system.
    - Save the script to a file, for example, `anagrams.py`.
    - Run the script using the command: python anagrams.py.

Example Output:
    Enter a word to find its anagrams: sample
    Anagrams of 'sample':
    maples

Additional Notes:
    - The dictionary file is downloaded from the specified URL. Ensure an active internet connection for successful download.
    - Anagrams are case-insensitive.
"""

import sys
import requests

def download_dictionary(url, file_name):
    """
    Download a dictionary file from a URL.

    Parameters:
        url (str): The URL from which to download the dictionary file.
        file_name (str): The name to save the downloaded file as.

    Raises:
        requests.RequestException: If an error occurs during the HTTP request.
    """
    try:
        response = requests.get(url)
        with open(file_name, 'wb') as f:
            f.write(response.content)
    except requests.RequestException as e:
        print("Error downloading dictionary from {}: {}".format(url, e))
        sys.exit(1)

def load_dictionary(file):
    """
    Open a text file & turn contents into a list of lowercase strings.

    Parameters:
        file (str): The name of the file to open.

    Returns:
        list: A list of lowercase strings containing the words from the file.
    """
    try:
        with open(file, encoding='utf-8') as in_file:
            loaded_txt = in_file.read().strip().split('\n')
            loaded_txt = [x.lower() for x in loaded_txt]
            return loaded_txt
    except IOError as e:
        print("{}\nError opening {}. Terminating program.".format(e, file))
        sys.exit(1)

def find_anagrams(word, word_list):
    """
    Find anagrams of a given word in a list of words.

    Parameters:
        word (str): The word to find anagrams for.
        word_list (list): A list of words to search for anagrams.

    Returns:
        list: A list of anagrams found in the word list.
    """
    word_sorted = sorted(word.lower())
    anagrams = [w for w in word_list if sorted(w) == word_sorted and w.lower() != word.lower()]
    return anagrams

def main():
    dictionary_url = "https://raw.githubusercontent.com/dwyl/english-words/master/words_alpha.txt"
    dictionary_file = "dictionary.txt"
    download_dictionary(dictionary_url, dictionary_file)

    user_input = input("Enter a word to find its anagrams: ").strip()

    word_list = load_dictionary(dictionary_file)
    anagrams = find_anagrams(user_input, word_list)

    if anagrams:
        print("Anagrams of '{}':".format(user_input))
        for anagram in anagrams:
            print(anagram)
    else:
        print("No anagrams found in dictionary for '{}'.".format(user_input))

if __name__ == "__main__":
    main()