danceschool_tags.py 文件源码

def get_item_by_key(passed_list, key, value):
    '''
    This one allows us to get one or more items from a list of
    dictionaries based on the value of a specified key, where
    both the key and the value can be variable names.  Does
    not work with None or null string passed values.
    '''

    if value in [None,'']:
        return

    if type(passed_list) in [QuerySet, PolymorphicQuerySet]:
        sub_list = passed_list.filter(**{key: value})
    else:
        sub_list = [x for x in passed_list if x.get(key) == value]

    if len(sub_list) == 1:
        return sub_list[0]
    return sub_list