Python Instagram Photo Downloader Project

"""Download media from one Instagram post that you have permission to save."""

from __future__ import annotations

import re
from pathlib import Path
from urllib.parse import urlsplit

import instaloader


SHORTCODE_PATTERN = re.compile(r"^[A-Za-z0-9_-]+$")


def extract_shortcode(post_url: str) -> str:
    """Extract a post or reel shortcode from a complete instagram.com URL."""
    parsed = urlsplit(post_url.strip())
    host = (parsed.hostname or "").lower()
    if host not in {"instagram.com", "www.instagram.com"}:
        raise ValueError("Use a complete instagram.com post or reel URL.")

    parts = [part for part in parsed.path.split("/") if part]
    if len(parts) < 2 or parts[0] not in {"p", "reel", "tv"}:
        raise ValueError("The URL must point to an Instagram post or reel.")

    shortcode = parts[1]
    if SHORTCODE_PATTERN.fullmatch(shortcode) is None:
        raise ValueError("The Instagram shortcode contains unexpected characters.")
    return shortcode


def download_post(post_url: str, output_dir: Path) -> bool:
    shortcode = extract_shortcode(post_url)
    output_dir.mkdir(parents=True, exist_ok=True)

    loader = instaloader.Instaloader(
        dirname_pattern=str(output_dir / "{target}"),
        filename_pattern="{shortcode}_{date_utc:%Y-%m-%d_%H-%M-%S}",
        download_videos=False,
        download_video_thumbnails=True,
        download_comments=False,
        download_geotags=False,
        save_metadata=False,
        post_metadata_txt_pattern="",
        quiet=True,
    )
    post = instaloader.Post.from_shortcode(loader.context, shortcode)
    return loader.download_post(post, target=shortcode)


def main() -> None:
    print("Instagram Photo Downloader")
    print("Only download your own posts or media you have permission to save.\n")
    post_url = input("Public post or reel URL: ").strip()
    output_dir = Path(input("Output folder [instagram_downloads]: ").strip() or "instagram_downloads")

    try:
        changed = download_post(post_url, output_dir)
    except ValueError as error:
        print(f"Invalid URL: {error}")
    except instaloader.exceptions.InstaloaderException as error:
        print(f"Instagram could not provide that post: {error}")
        print("The post may be private, unavailable, rate-limited, or require a logged-in session.")
    except OSError as error:
        print(f"Could not save the download: {error}")
    else:
        print("Download complete." if changed else "The media was already downloaded.")


if __name__ == "__main__":
    main()