def load(self, requirements_file=None):
        """Load or reload requirements from a requirements.txt file.

        :param requirements_file: if not given, the filename used from
            initialization will be read again.
        """
        if requirements_file is None:
            requirements_file = self.filename
            if requirements_file is None:
                raise ValueError("no filename provided")
        elif isinstance(requirements_file, text_type):
            requirements_file = Path(requirements_file)
        self.clear()
        with requirements_file.open() as f:
            self.loads(f.read())

        if isinstance(requirements_file, (text_type, Path)):
            self.filename = requirements_file
def search(self, search_base=None, search_scope=None,
               search_filter=None, attributes=None, paged_size=5,
               size_limit=0, paged_cookie=None):
        s_filter = list()
        candidates = list()
        self.response = list()
        self.result = dict()

        try:
            if isinstance(search_filter, bytes):
                # We need to convert to unicode otherwise pyparsing will not
                # find the u"ö"
                search_filter = to_unicode(search_filter)
            expr = Connection._parse_filter()
            s_filter = expr.parseString(search_filter).asList()[0]
        except pyparsing.ParseBaseException as exx:
            # Just for debugging purposes
            s = "{!s}".format(exx)

        for item in s_filter:
            if item[0] in self.operation:
                candidates = self.operation.get(item[0])(search_base,
                                                         s_filter)
        self.response = Connection._deDuplicate(candidates)

        return True