core: Add get_official_territories()

babel/core.py

@@ -25,6 +25,7 @@
     'get_cldr_version',
     'get_global',
     'get_locale_identifier',
+    'get_official_territories',
     'negotiate_locale',
     'parse_locale',
 ]
@@ -42,6 +43,7 @@
         "parent_exceptions",
         "script_aliases",
         "territory_aliases",
+        "territory_codes",
         "territory_currencies",
         "territory_languages",
         "territory_zones",
@@ -89,6 +91,7 @@ def get_global(key: _GLOBAL_KEY) -> Mapping[str, Any]:
     - ``parent_exceptions``
     - ``script_aliases``
     - ``territory_aliases``
+    - ``territory_codes``
     - ``territory_currencies``
     - ``territory_languages``
     - ``territory_zones``
@@ -1379,3 +1382,27 @@ def get_cldr_version() -> str:
     :rtype: str
     """
     return str(get_global("cldr")["version"])
+
+
+def get_official_territories() -> frozenset[str]:
+    """Return the ISO 3166-1 alpha-2 territory codes known to Babel.
+
+    This is the set of two-letter territory (country) codes that the CLDR
+    provides, with deprecated codes and the ISO user-assigned ranges removed.
+
+    >>> codes = get_official_territories()
+    >>> 'US' in codes
+    True
+    >>> 'ZZ' in codes  # reserved for private use
+    False
+
+    Since the data comes from the CLDR, the returned set does not match the
+    official ISO 3166-1 list exactly: a few territories that the CLDR omits
+    are missing, and a handful of exceptionally reserved codes (such as
+    ``EU``) are included.
+
+    .. versionadded:: 2.19
+
+    :rtype: frozenset[str]
+    """
+    return frozenset(get_global('territory_codes'))

docs/api/core.rst

@@ -38,3 +38,5 @@ Utility Functions
 .. autofunction:: get_locale_identifier
 
 .. autofunction:: get_cldr_version
+
+.. autofunction:: get_official_territories

scripts/import_cldr.py

@@ -98,6 +98,12 @@ def _parse_currency_date(s):
     return tuple(map(int, parts + [1] * (3 - len(parts))))
 
 
+def _is_user_assigned_territory(code):
+    # ISO 3166-1 reserves these code ranges for private use, so they never
+    # denote an actual territory.
+    return code in ('AA', 'ZZ') or 'QM' <= code <= 'QZ' or 'XA' <= code <= 'XZ'
+
+
 def _currency_sort_key(tup):
     code, start, end, tender = tup
     return int(not tender), start or (1, 1, 1)
@@ -359,6 +365,25 @@ def parse_global(srcdir, sup):
                 'official_status': language.attrib.get('officialStatus'),
             }
         territory_languages[territory.attrib['type']] = languages
+
+    # ISO 3166-1 alpha-2 territory codes (see GH #904).
+    # CLDR's supplemental code mappings list every territory code alongside its
+    # ISO numeric and alpha-3 equivalents. We keep the two-letter codes that
+    # have a numeric ISO code assigned (this drops exceptionally reserved codes
+    # such as EA or IC), and skip the ISO user-assigned ranges as well as any
+    # code CLDR records as a deprecated alias.
+    territory_codes = set()
+    for mapping in sup.findall('.//codeMappings/territoryCodes'):
+        code = mapping.attrib['type']
+        if len(code) != 2 or not code.isalpha():
+            continue
+        if 'numeric' not in mapping.attrib:
+            continue
+        if code in territory_aliases or _is_user_assigned_territory(code):
+            continue
+        territory_codes.add(code)
+    global_data['territory_codes'] = tuple(sorted(territory_codes))
+
     return global_data
 
 

tests/test_core.py

@@ -183,3 +183,18 @@ def test_locale_parse_empty():
 
 def test_get_cldr_version():
     assert core.get_cldr_version() == "48"
+
+
+def test_get_official_territories():
+    codes = core.get_official_territories()
+    assert isinstance(codes, frozenset)
+    # A good spread of everyday country codes should be present.
+    assert {'US', 'DE', 'FR', 'JP', 'ZA', 'BR'} <= codes
+    # All codes are two uppercase letters.
+    assert all(len(code) == 2 and code.isalpha() and code.isupper() for code in codes)
+    # The ISO user-assigned ranges are excluded.
+    assert 'ZZ' not in codes
+    assert not any('XA' <= code <= 'XZ' for code in codes)
+    # Deprecated codes such as Yugoslavia or the USSR are excluded.
+    assert 'YU' not in codes
+    assert 'SU' not in codes