Downloads a file from the given URL and saves it to the specified file path.

download_file.py

import os
import requests
import shutil
from tqdm import tqdm


def download_file(url: str, file_path: str) -> None:
    """
    Downloads a file from the given URL and saves it to the specified file path.
    Shows a progress bar using the tqdm library.
    """
    # Get the file name from the URL
    file_name = os.path.basename(url)

    # Append .tmp extension to the file name
    tmp_file_path = os.path.join(file_path, file_name + ".tmp")

    # Check if the file already exists and has the correct size
    if os.path.exists(file_path) and os.path.getsize(file_path) == int(requests.head(url).headers["Content-Length"]):
        print(f"Skipping download, file {file_path} already exists.")
        return

    # Check if the temporary file already exists and resume download
    resume_byte_pos = 0
    if os.path.exists(tmp_file_path):
        resume_byte_pos = os.path.getsize(tmp_file_path)
        print(f"Resuming download from byte position {resume_byte_pos}.")

    # Send a GET request to the URL and get the response as a stream
    headers = {"Range": f"bytes={resume_byte_pos}-"}
    with requests.get(url, stream=True, allow_redirects=True, headers=headers) as response:
        # Raise an exception if the response status code is not in the 200-299 range
        if not response.ok:
            response.raise_for_status()

        # Get the total size of the file from the response headers
        total_size = int(response.headers.get("content-length", 0))

        # Open the temporary file in binary write mode
        with open(tmp_file_path, "ab") as f, tqdm(total=total_size, initial=resume_byte_pos, unit="B", unit_scale=True, desc=file_name) as pbar:
            # Read the response in chunks and write each chunk to the file
            for chunk in response.iter_content(chunk_size=8192):
                if chunk:
                    f.write(chunk)
                    pbar.update(len(chunk))

    # Move the temporary file to the target file upon successful download
    shutil.move(tmp_file_path, os.path.join(file_path, file_name))
    print(f"Download of {file_name} complete.")