qpdf/build-scripts/download-external-libs

#!/usr/bin/env python3
import json
import os
import requests
import sys
from zipfile import ZipFile


def warn(*args, **kwargs):
    print(*args, **kwargs, file=sys.stderr)


def download_file(url, local_filename):
    # From https://stackoverflow.com/questions/16694907/
    # download-large-file-in-python-with-requests
    if os.path.exists(local_filename):
        warn('Using existing', local_filename)
        return
    warn('Downloading', local_filename)
    with requests.get(url, stream=True) as r:
        r.raise_for_status()
        with open(local_filename, 'wb') as f:
            for chunk in r.iter_content(chunk_size=8192):
                f.write(chunk)
    return local_filename


bin_name = 'qpdf-external-libs-bin.zip'
src_name = 'qpdf-external-libs-src.zip'
dir_name = 'external-libs-dist'
os.makedirs(dir_name, exist_ok=True)

r = requests.get(
    'https://api.github.com/repos/qpdf/external-libs/releases')
releases = json.loads(r.text)

# Help diagnose occasional failure where some releases don't have
# 'prerelease'. I've never seen this in attempts to reproduce.
print("---- github API output for external-libs releaes ----")
print(json.dumps(releases, indent=2, separators=(',', ': ')))
print("--------")

by_tag = sorted(
    [(r['tag_name'], r) for r in releases
     if r['prerelease'] is False],
    reverse=True)
latest = by_tag[0][1]
bin_url = None
src_url = None
for i in latest['assets']:
    if i['name'] == bin_name:
        bin_url = i['browser_download_url']
    elif i['name'] == src_name:
        src_url = i['browser_download_url']
print(bin_url)
download_file(bin_url, f'{dir_name}/{bin_name}')
download_file(src_url, f'{dir_name}/{src_name}')

print('\n** external library information **')
with ZipFile(f'{dir_name}/{src_name}') as z1:
    with z1.open('external-libs-src/versions') as z2:
        print(z2.read().decode())