def read_installed_packages_list(self, from_location):
        """
        Reads a given configuration file, and updates the
        internal installed packages list.

        :param from_location: a path (string) to a directory containing an installed.lst file
        """

        try:
            installed_list_file=open(from_location+"/installed.lst")
        except __HOLE__:
            # maybe not a problem, but
            # FIXME: print a warning if exists,
            # but cannot be read (permissions)
            pass
        else:
            # read from file and
            # create a dictionary
            for line in installed_list_file:
                l=line.rstrip().split(' ')
                if l:
                    self.installed_packages_list[l[0]]=\
                        this_package=self.package_info(
                        from_location, # from which configuration files it comes
                        l[0], # name
                        l[1], # timestamp
                        l[2], # human-readable size
                        urllib.unquote(l[3]), # source on the web
                        urllib.unquote(l[4]))  # where installed
                else:
                    pass# skip blank lines (there shouldn't be any)
dataset/ETHPy150Open lisa-lab/pylearn2/pylearn2/dataset_get/dataset_resolver.py/dataset_resolver.read_installed_packages_list