'If the requirement is frozen to pypi, check for a new version.'

def check_pypi(self):

    for dist in pip.get_installed_distributions():
        name = dist.project_name
        if (name in self.reqs.keys()):
            self.reqs[name]['dist'] = dist
    pypi = ServerProxy('https://pypi.python.org/pypi')
    for (name, req) in list(self.reqs.items()):
        if req['url']:
            continue
        elif ('dist' in req):
            dist = req['dist']
            dist_version = LooseVersion(dist.version)
            available = pypi.package_releases(req['pip_req'].name, True)
            available_version = self._available_version(dist_version, available)
            if (not available_version):
                msg = self.style.WARN('release    is    not    on    pypi    (check    capitalization    and/or    --extra-index-url)')
            elif (self.options['show_newer'] and (dist_version > available_version)):
                msg = self.style.INFO('{0}    available    (newer    installed)'.format(available_version))
            elif (available_version > dist_version):
                msg = self.style.INFO('{0}    available'.format(available_version))
            else:
                msg = 'up    to    date'
                del self.reqs[name]
                continue
            pkg_info = self.style.BOLD('{dist.project_name}    {dist.version}'.format(dist=dist))
        else:
            msg = 'not    installed'
            pkg_info = name
        print '{pkg_info:40}    {msg}'.format(pkg_info=pkg_info, msg=msg)
        del self.reqs[name]
