def get_left_ngrams(mention, window=<NUM_LIT:3>, attrib="<STR_LIT>", n_min=<NUM_LIT:1>, n_max=<NUM_LIT:1>, lower=True):
span = _to_span(mention)<EOL>i = span.get_word_start_index()<EOL>for ngram in tokens_to_ngrams(<EOL>getattr(span.sentence, attrib)[max(<NUM_LIT:0>, i - window) : i],<EOL>n_min=n_min,<EOL>n_max=n_max,<EOL>lower=lower,<EOL>):<EOL><INDENT>yield ngram<EOL><DEDENT>
Get the ngrams within a window to the *left* from the sentence Context.

    For higher-arity Candidates, defaults to the *first* argument.

    :param mention: The Mention to evaluate. If a candidate is given, default
        to its first Mention.
    :param window: The number of tokens to the left of the first argument to
        return.
    :param attrib: The token attribute type (e.g. words, lemmas, poses)
    :param n_min: The minimum n of the ngrams that should be returned
    :param n_max: The maximum n of the ngrams that should be returned
    :param lower: If True, all ngrams will be returned in lower case
    :rtype: a *generator* of ngrams