Instructing a function to be called with a specific argument without executing it

Question

I am trying to encode logic to filter a Pandas dataframe. I\'d like to encode the logic as a dictionary, with the subgroup name as the key, and the function to filter for the su

Answer 1

You can consider functools.partialmethod, which allows you to specify any number of args or kwargs:

from functools import partialmethod

mappings = {'Jets Fans': partialmethod(BaseFilter.for_jets_fans, 'Jets'),
            'Patriots Fans': partialmethod(BaseFilter.for_patriots_fans, 'Patriots'),
            'NFC Fans': partialmethod(BaseFilter.for_team_fans, 'Bears', 'Packers')}

Answer 2

If BaseFilter.for_team_fans is the common base function for every entry in your analytics_table_mappings dict, then you can factor it out. Since that leaves only one property, the dict could be reduced to a simple key: args pairing, such as

analytics_table_mappings = {
    "Jets Fans": "Jets",
    "Patriots Fans": "Patriots",
    "NFC Fans": ["Bears", "Packers", ...]
}

and then maybe incorporate the logic into a simple class:

class Teams:
    analytics_table_mappings = {
        "Jets Fans": "Jets",
        "Patriots Fans": "Patriots",
        "NFC Fans": ["Bears", "Packers", ...]
    }

    @classmethod
    def get_teams(cls, fan_type):
        if fan_type not in cls.analytics_table_mappings:
            return 'Invalid fan type: {}'.format(fan_type)
        teams = cls.analytics_table_mappings[fan_type]
        if not isinstance(teams, list):
            teams = [teams]
        return [cls.for_team_fans(team) for team in teams]

    def for_team_fans(team_name):
        # your logic here
        return team_name


print(Teams().get_teams("Jets Fans"))
>> ['Jets']

print(Teams().get_teams("Patriots Fans"))
>> ['Patriots']

print(Teams().get_teams("NFC Fans"))
>> ['Bears', 'Packers', ...]

print(Teams().get_teams("Argonauts Fans"))
>> Invalid fan type: Argonauts Fans