Check locally installed packages against one or more package indexes for updates and list them. Using subprocess instead of stdout (wasn't working on my MacPython 2.6.1)

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 sys
import xmlrpclib
import subprocess
from distutils.version import StrictVersion, LooseVersion


def get_local_packages():
    """
    Call pip's freeze -l
    
    returns a list of package_name, version tuples
    """
    cmd = ' '.join(['pip', 'freeze', '-l'])
    process = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True)
    out, err = process.communicate()

    pkgs = out.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)