#! /usr/bin/env nix-shell
#! nix-shell -i python3 -p 'python3.withPackages(ps: with ps; [ requests toolz ])'
"""
Update a Python package expression by passing in the `.nix` file, or the directory containing it.
You can pass in multiple files or paths.
You'll likely want to use
``
$ ./update-python-libraries ../../pkgs/development/python-modules/*
``
to update all libraries in that folder.
"""
import argparse
import logging
import os
import re
import requests
import toolz
from concurrent.futures import ThreadPoolExecutor as pool
INDEX = "https://pypi.io/pypi"
"""url of PyPI"""
EXTENSIONS = ['tar.gz', 'tar.bz2', 'tar', 'zip', '.whl']
"""Permitted file extensions. These are evaluated from left to right and the first occurance is returned."""
import logging
logging.basicConfig(level=logging.INFO)
def _get_values(attribute, text):
"""Match attribute in text and return all matches.
:returns: List of matches.
"""
regex = '{}\s+=\s+"(.*)";'.format(attribute)
regex = re.compile(regex)
values = regex.findall(text)
return values
def _get_unique_value(attribute, text):
"""Match attribute in text and return unique match.
:returns: Single match.
"""
values = _get_values(attribute, text)
n = len(values)
if n > 1:
raise ValueError("found too many values for {}".format(attribute))
elif n == 1:
return values[0]
else:
raise ValueError("no value found for {}".format(attribute))
def _get_line_and_value(attribute, text):
"""Match attribute in text. Return the line and the value of the attribute."""
regex = '({}\s+=\s+"(.*)";)'.format(attribute)
regex = re.compile(regex)
value = regex.findall(text)
n = len(value)
if n > 1:
raise ValueError("found too many values for {}".format(attribute))
elif n == 1:
return value[0]
else:
raise ValueError("no value found for {}".format(attribute))
def _replace_value(attribute, value, text):
"""Search and replace value of attribute in text."""
old_line, old_value = _get_line_and_value(attribute, text)
new_line = old_line.replace(old_value, value)
new_text = text.replace(old_line, new_line)
return new_text
def _fetch_page(url):
r = requests.get(url)
if r.status_code == requests.codes.ok:
return r.json()
else:
raise ValueError("request for {} failed".format(url))
def _get_latest_version_pypi(package, extension):
"""Get latest version and hash from PyPI."""
url = "{}/{}/json".format(INDEX, package)
json = _fetch_page(url)
version = json['info']['version']
for release in json['releases'][version]:
if release['filename'].endswith(extension):
# TODO: In case of wheel we need to do further checks!
sha256 = release['digests']['sha256']
break
else:
sha256 = None
return version, sha256
def _get_latest_version_github(package, extension):
raise ValueError("updating from GitHub is not yet supported.")
FETCHERS = {
'fetchFromGitHub' : _get_latest_version_github,
'fetchPypi' : _get_latest_version_pypi,
'fetchurl' : _get_latest_version_pypi,
}
DEFAULT_SETUPTOOLS_EXTENSION = 'tar.gz'
FORMATS = {
'setuptools' : DEFAULT_SETUPTOOLS_EXTENSION,
'wheel' : 'whl'
}
def _determine_fetcher(text):
# Count occurences of fetchers.
nfetchers = sum(text.count('src = {}'.format(fetcher)) for fetcher in FETCHERS.keys())
if nfetchers == 0:
raise ValueError("no fetcher.")
elif nfetchers > 1:
raise ValueError("multiple fetchers.")
else:
# Then we check which fetcher to use.
for fetcher in FETCHERS.keys():
if 'src = {}'.format(fetcher) in text:
return fetcher
def _determine_extension(text, fetcher):
"""Determine what extension is used in the expression.
If we use:
- fetchPypi, we check if format is specified.
- fetchurl, we determine the extension from the url.
- fetchFromGitHub we simply use `.tar.gz`.
"""
if fetcher == 'fetchPypi':
try:
format = _get_unique_value('format', text)
except ValueError as e:
format = None # format was not given
try:
extension = _get_unique_value('extension', text)
except ValueError as e:
extension = None # extension was not given
if extension is None:
if format is None:
format = 'setuptools'
extension = FORMATS[format]
elif fetcher == 'fetchurl':
url = _get_unique_value('url', text)
extension = os.path.splitext(url)[1]
if 'pypi' not in url:
raise ValueError('url does not point to PyPI.')
elif fetcher == 'fetchFromGitHub':
raise ValueError('updating from GitHub is not yet implemented.')
return extension
def _update_package(path):
# Read the expression
with open(path, 'r') as f:
text = f.read()
# Determine pname.
pname = _get_unique_value('pname', text)
# Determine version.
version = _get_unique_value('version', text)
# First we check how many fetchers are mentioned.
fetcher = _determine_fetcher(text)
extension = _determine_extension(text, fetcher)
new_version, new_sha256 = _get_latest_version_pypi(pname, extension)
if new_version == version:
logging.info("Path {}: no update available for {}.".format(path, pname))
return False
if not new_sha256:
raise ValueError("no file available for {}.".format(pname))
text = _replace_value('version', new_version, text)
text = _replace_value('sha256', new_sha256, text)
with open(path, 'w') as f:
f.write(text)
logging.info("Path {}: updated {} from {} to {}".format(path, pname, version, new_version))
return True
def _update(path):
# We need to read and modify a Nix expression.
if os.path.isdir(path):
path = os.path.join(path, 'default.nix')
# If a default.nix does not exist, we quit.
if not os.path.isfile(path):
logging.info("Path {}: does not exist.".format(path))
return False
# If file is not a Nix expression, we quit.
if not path.endswith(".nix"):
logging.info("Path {}: does not end with `.nix`.".format(path))
return False
try:
return _update_package(path)
except ValueError as e:
logging.warning("Path {}: {}".format(path, e))
return False
def main():
parser = argparse.ArgumentParser()
parser.add_argument('package', type=str, nargs='+')
args = parser.parse_args()
packages = map(os.path.abspath, args.package)
with pool() as p:
count = list(p.map(_update, packages))
logging.info("{} package(s) updated".format(sum(count)))
if __name__ == '__main__':
main()