formatting; 32 apikey length

mp_api/client/mprester.py

@@ -79,10 +79,10 @@ class MPRester:
 
     def __init__(
         self,
-        api_key=DEFAULT_API_KEY,
-        endpoint=DEFAULT_ENDPOINT,
-        notify_db_version=False,
-        include_user_agent=True,
+        api_key: str = DEFAULT_API_KEY,
+        endpoint: str = DEFAULT_ENDPOINT,
+        notify_db_version: bool = False,
+        include_user_agent: bool = True,
         monty_decode: bool = True,
         use_document_model: bool = True,
         session: Session = None,
@@ -121,9 +121,9 @@ def __init__(
             headers (dict): Custom headers for localhost connections.
         """
 
-        if api_key and len(api_key) == 16:
+        if api_key and len(api_key) != 32:
             raise ValueError(
-                "Please use a new API key from https://next-gen.materialsproject.org/api "
+                "Please use a new API key from https://materialsproject.org/api "
                 "Keys for the new API are 32 characters, whereas keys for the legacy "
                 "API are 16 characters."
             )