re-add normalize_scope and Retry class to util.py

Author: dieser-niko

spotipy/util.py

@@ -38,3 +38,53 @@ def get_host_port(netloc):
         port = None
 
     return host, port
+
+
+def normalize_scope(scope):
+    """Normalize the scope to verify that it is a list or tuple. A string
+    input will split the string by commas to create a list of scopes.
+    A list or tuple input is used directly.
+
+    Parameters:
+        - scope - a string representing scopes separated by commas,
+                  or a list/tuple of scopes.
+    """
+    if scope:
+        if isinstance(scope, str):
+            scopes = scope.split(',')
+        elif isinstance(scope, list) or isinstance(scope, tuple):
+            scopes = scope
+        else:
+            raise Exception(
+                "Unsupported scope value, please either provide a list of scopes, "
+                "or a string of scopes separated by commas."
+            )
+        return " ".join(sorted(scopes))
+    else:
+        return None
+
+
+class Retry(urllib3.Retry):
+    """
+    Custom class for printing a warning when a rate/request limit is reached.
+    """
+    def increment(
+            self,
+            method: str | None = None,
+            url: str | None = None,
+            response: urllib3.BaseHTTPResponse | None = None,
+            error: Exception | None = None,
+            _pool: urllib3.connectionpool.ConnectionPool | None = None,
+            _stacktrace: TracebackType | None = None,
+    ) -> urllib3.Retry:
+        if response:
+            retry_header = response.headers.get("Retry-After")
+            if self.is_retry(method, response.status, bool(retry_header)):
+                logging.warning("Your application has reached a rate/request limit. "
+                                f"Retry will occur after: {retry_header}")
+        return super().increment(method,
+                                 url,
+                                 response=response,
+                                 error=error,
+                                 _pool=_pool,
+                                 _stacktrace=_stacktrace)