cache key does not include prefix (#5)

src/fastapi_redis_cache/key_gen.py

@@ -10,16 +10,33 @@
 ALWAYS_IGNORE_ARG_TYPES = [Response, Request]
 
 
-def get_cache_key(func: Callable, ignore_arg_types: List[ArgType], *args: List, **kwargs: Dict) -> str:
-    """Ganerate a string that uniquely identifies the function and values of all arguments."""
+def get_cache_key(func: Callable, prefix: str, ignore_arg_types: List[ArgType], *args: List, **kwargs: Dict) -> str:
+    """Ganerate a string that uniquely identifies the function and values of all arguments.
+
+    Args:
+        func (`Callable`): Path operation function for an API endpoint.
+        prefix (`str`): Customizable namespace value that will prefix all cache keys.
+        ignore_arg_types (`List[ArgType]`): Each argument to the API endpoint function is
+            used to compose the cache key by calling `str(arg)`. If there are any keys that
+            should not be used in this way (i.e., because their value has no effect on the
+            response, such as a `Request` or `Response` object) you can remove them from
+            the cache key by including their type as a list item in ignore_key_types.
+
+    Returns:
+        `str`: Unique identifier for `func`, `*args` and `**kwargs` that can be used as a
+            Redis key to retrieve cached API response data.
+    """
+
     if not ignore_arg_types:
         ignore_arg_types = []
     ignore_arg_types.extend(ALWAYS_IGNORE_ARG_TYPES)
+    prefix = f"{prefix}:" if prefix else ""
+
     sig = signature(func)
     sig_params = sig.parameters
     func_args = get_func_args(sig, *args, **kwargs)
     args_str = get_args_str(sig_params, func_args, ignore_arg_types)
-    return f"{func.__module__}.{func.__name__}({args_str})"
+    return f"{prefix}{func.__module__}.{func.__name__}({args_str})"
 
 
 def get_func_args(sig: Signature, *args: List, **kwargs: Dict) -> "OrderedDict[str, Any]":