human
Here's a good function header given the following:
I wrote the below code

    T = current.T
    settings.base.system_name_short = T('Sahana')
    settings.base.prepopulate += ('WACOP', 'default/users', 'WACOP/Demo')
    settings.base.theme = 'WACOP'
    settings.ui.social_buttons = True
    settings.security.self_registration = False
    settings.auth.registration_requires_verification = True
    settings.auth.registration_requires_approval = True
    settings.auth.registration_requests_organisation = True
    settings.auth.registration_organisation_required = True
    settings.mail.approver = 'ADMIN'
    settings.auth.registration_link_user_to = {'staff': T('Staff')}
    settings.auth.registration_link_user_to_default = ['staff']
    settings.auth.registration_roles = {'organisation_id': ['USER']}
    settings.auth.show_utc_offset = False
    settings.auth.show_link = False
    settings.security.policy = 7
    settings.security.map = True
    def audit_write(method, tablename, form, record, representation):
        if (tablename in ('event_incident', 'pr_group')):
            return True
        else:
            return False
    settings.security.audit_write = audit_write
    settings.L10n.languages = OrderedDict([('en', 'English'), ('es', 'Espa\xc3\xb1ol')])
    settings.L10n.default_language = 'en'
    settings.L10n.utc_offset = '-0800'
    settings.L10n.date_format = '%b    %d    %Y'
    settings.L10n.decimal_separator = '.'
    settings.L10n.thousands_separator = ','
    settings.L10n.default_country_code = 1
    settings.ui.label_mobile_phone = 'Cell    Phone'
    settings.ui.label_postcode = 'ZIP    Code'
    settings.msg.require_international_phone_numbers = False
    settings.base.paper_size = T('Letter')
    settings.search.dates_auto_range = True
    settings.gis.countries = ('US',)
    settings.gis.check_within_parent_boundaries = False
    settings.gis.geonames_username = 'mcop'
    settings.gis.legend = 'float'
    settings.gis.location_represent_address_only = 'icon'
    settings.gis.poi_create_resources = None
    settings.ui.datatables_pagingType = 'bootstrap'
   ...

What's a good function header?
assistant
#Here's a good function header.

def config(settings):