Add auth_key_is_free_account()

Author: daniel-jones-dev

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   returned by `get_usage()`.
 * Add `Translator.translate_document_wait_until_done()` to poll translation
   status until translation is complete or fails.
+* Add `auth_key_is_free_account()` utility function.
 ### Changed
 ### Deprecated
 * Deprecate `limit_exceeded` and `any_limit_exceeded` properties of `Usage`

deepl/__init__.py

@@ -32,6 +32,7 @@
 )
 
 from .util import (  # noqa
+    auth_key_is_free_account,
     convert_tsv_to_dict,
     convert_dict_to_tsv,
     validate_glossary_term,

deepl/translator.py

@@ -467,7 +467,7 @@ def __init__(
         if server_url is None:
             server_url = (
                 self._DEEPL_SERVER_URL_FREE
-                if auth_key.endswith(":fx")
+                if util.auth_key_is_free_account(auth_key)
                 else self._DEEPL_SERVER_URL
             )
 

deepl/util.py

@@ -34,6 +34,12 @@ def get_int_safe(d: dict, key: str) -> Optional[int]:
         return None
 
 
+def auth_key_is_free_account(auth_key: str) -> bool:
+    """Returns True if the given authentication key belongs to a DeepL API Free
+    account, otherwise False."""
+    return auth_key.endswith(":fx")
+
+
 def validate_glossary_term(term: str) -> None:
     """Checks if the given glossary term contains any disallowed characters.