class Extract(Func):
    """
    Performs extraction of `what_to_extract` from `*expressions`.
    Arguments:
        *expressions (string): Only single value is supported, should be field name to
                               extract from.
        what_to_extract (string): Extraction specificator.
    Returns:
        class: Func() expression class, representing 'EXTRACT(`what_to_extract` FROM `*expressions`)'.
    """
function = 'EXTRACT'
Django count grouping by year/month without extra