def _get_metazone_cities(metazone, limit=5):
zones = [tz for mz, tz in METAZONE_MAPPING_TO_TZ.items() if mz[0] == metazone]
cities = sorted([territory[1] for tz, territory in TIMEZONE_NAMES.items() if tz in zones])
if len(cities) > limit:
return ", ".join(map(force_text, cities[:limit])) + ", ..."
else:
return ", ".join(map(force_text, cities))
def get_timezones_cities(timezones=None, exclude=None):
"""Returns a list of choices with (timezone code, exemplar city)-pairs, grouped by their territory.
Only timezones present in the timezones argument, and not present in the exclude argument, are returned.
"""
# We require sorting for the groupby
timezones = COMMON_TIMEZONES if timezones is None else timezones
exclude = exclude if exclude else []
values = sorted(TIMEZONE_NAMES.items(), key=lambda item: orig_str(item[1][0]))
result = []
for territory, zones in itertools.groupby(values, lambda item: item[1][0]):
items = [(k, v[1]) for k, v in zones if k in timezones and k not in exclude]
if items:
result.append((territory, items))
return result
