check_for_updates.py

#!/usr/bin/env python
"""
Use pip to get a list of local packages to check against one or more package
indexes for updated versions.
"""
import pip
import sys
import xmlrpclib
from cStringIO import StringIO
from distutils.version import StrictVersion, LooseVersion


def get_local_packages():
    """
    Call pip's freeze -l

    returns a list of package_name, version tuples
    """
    sys.stdout = mystdout = StringIO()
    pip.main(['freeze', '-l'])
    sys.stdout = sys.__stdout__

    pkgs = mystdout.getvalue().split('\n')
    return [p.split('==') for p in pkgs]


def find_current_version(package, index_urls=None):
    """
    Using the XMLRPC method available for PyPI, get the most recent version
    of <package> from each of the index_urls and figure out which one (if any)
    is higher

    Returns a tuple of the index with the higher version and the version it has
    """
    if index_urls is None:
        index_urls = ['http://pypi.python.org/pypi']
    cur_version = '0'
    cur_index = ''
    for index_url in index_urls:
        pypi = xmlrpclib.ServerProxy(index_url, xmlrpclib.Transport())
        pypi_hits = pypi.package_releases(package)
        if len(pypi_hits) > 0:
            if compare_versions(pypi_hits[0], cur_version) == 1:
                cur_version = pypi_hits[0]
                cur_index = index_url

    return cur_index, cur_version


def compare_versions(version1, version2):
    """
    Compare 2 versions, starting with StrictVersion, and falling back on
    LooseVersion
    """
    try:
        return cmp(StrictVersion(version1), StrictVersion(version2))
    # in case of abnormal version number, fall back to LooseVersion
    except ValueError:
        return cmp(LooseVersion(version1), LooseVersion(version2))


def output_line(pkg_name, new_version, old_version, index_url):
    """
    Output the line showing the formatted information
    """
    msg = "%(bd)s%(pkg_name)s%(nm)s (%(new)s) via %(index)s. Currently %(old)s."
    params = {
        'bd': BOLD,
        'nm': NORMAL,
        'pkg_name': pkg_name,
        'new': new_version,
        'old': old_version,
        'index': index_url,
    }
    print msg % params


NEWER = lambda x, y: compare_versions(str(x), y) == 1


if __name__ == '__main__':
    import curses
    curses.setupterm()
    CLEAR_SCREEN = curses.tigetstr('clear')
    BOLD = curses.tigetstr("bold")
    NORMAL = curses.tigetstr('sgr0')

    if len(sys.argv) > 1:
        indexes = sys.argv[1:]
    else:
        indexes = ['http://pypi.python.org/pypi']
    print CLEAR_SCREEN + BOLD + "Packages with newer versions:" + NORMAL
    print ""

    for pkg in get_local_packages():
        # pip outputs a single 0 at the end of the list. Ignore it.
        if len(pkg) < 2:
            continue

        index, current_version = find_current_version(pkg[0], index_urls=indexes)
        if current_version and NEWER(str(current_version), pkg[1]):
            output_line(pkg[0], current_version, pkg[1], index)