Document utilities

great_ai/utilities/language/is_english.py

@@ -4,6 +4,28 @@ from langcodes import standardize_tag, tag_distance
 
 
 def is_english(language_code: Optional[str]) -> bool:
+    """Decide whether the `language_code` is of an English language.
+
+    A thin wrapper over [langcodes](https://github.com/rspeer/langcodes) for convenient
+    language tagging.
+
+    Examples:
+        >>> is_english('en-US')
+        True
+
+        >>> is_english(None)
+        False
+
+        >>> is_english('und')
+        False
+
+    Args:
+        language_code: Language code, for example, returned by
+            `[great_ai.utilities.predict_language][].
+
+    Returns:
+        Boolean indicating whether it's English.
+    """
     if not language_code:
         language_code = "und"