Feature/country metadata

[mymi14s]

Rich Country Metadata

Summary

This PR introduces country metadata (currency_name, currency_symbol, calling_code, capital_city, utc_offset, continent, date_format, official_language and timezones) to the Country object and enhances Django Rest Framework serialization to easily expose this data to frontends.

Features

• Rich Metadata on Country Objects:
  Access essential country details directly:

  • currency_name & currency_symbol (e.g., "British pound", "£")
  • calling_code (e.g., "+44")
  • capital_city (e.g., "London")
  • utc_offset, continent, date_format, official_language, timezones.

• Optimized:
  Metadata is sourced from a local YAML file and cached in memory.

• DRF Integration:
  Added the fields to serializers.

Usage

Python / Django Models

from django_countries.fields import Country

nz = Country('NZ')
print(f"{nz.name} uses {nz.currency_name} ({nz.currency_symbol})")
# Output: New Zealand uses New Zealand dollar ($)

# Works directly on model instances too
user.country.calling_code  # e.g., '+64'

# Access rich metadata properties directly
print(f"Capital: {nz.capital_city}")
print(f"Calling Code: {nz.calling_code}")
print(f"Languages: {', '.join(nz.official_language)}")

# Or accessing from a model instance
class Person(models.Model):
    country = CountryField()

person = Person.objects.get(name='Alice')
person.country.currency_name
person.country.currency_symbol
person.country.calling_code
person.country.utc_offset
person.country.capital_city
person.country.continent
person.country.date_format
person.country.official_language
person.country.timezones

Sample Output

Here is the data available for the Country('NZ') object:

Property	Value	Description
currency_name	'New Zealand dollar'	Full name of the currency.
currency_symbol	'$'	Currency symbol.
calling_code	'+64'	International dialing code.
utc_offset	'-11:00'	Primary UTC offset.
capital_city	'Wellington'	Capital city name.
continent	'Oceania'	Continent the country belongs to.
date_format	'DD/MM/YYYY'	Common date format used.
official_language	['English', 'Māori', 'New Zealand Sign Language']	List of official languages.
timezones	['UTC−11:00', 'UTC−10:00', 'UTC+12:00', 'UTC+12:45', 'UTC+13:00']	All timezones observed.

[mymi14s]

@SmileyChris some of the changes to the code style (imports) was due to my use of python black to format the source files.