Add type annotations for Spotify JSON objects

setup.py

@@ -26,6 +26,7 @@
     author_email="[email protected]",
     url='https://spotipy.readthedocs.org/',
     install_requires=[
+        'typing_extensions>=3.10.0',
         'requests>=2.25.0',
         'six>=1.15.0',
         'urllib3>=1.26.0'

spotipy/cache_handler.py

@@ -6,8 +6,11 @@
 import json
 import logging
 import os
-from spotipy.util import CLIENT_CREDS_ENV_VARS
 from abc import ABC, abstractmethod
+from typing import Optional
+
+from spotipy.json_types import TokenInfo
+from spotipy.util import CLIENT_CREDS_ENV_VARS
 
 logger = logging.getLogger(__name__)
 
@@ -23,13 +26,13 @@ class CacheHandler(ABC):
     """
 
     @abstractmethod
-    def get_cached_token(self):
+    def get_cached_token(self) -> Optional[TokenInfo]:
         """
         Get and return a token_info dictionary object.
         """
 
     @abstractmethod
-    def save_token_to_cache(self, token_info):
+    def save_token_to_cache(self, token_info: TokenInfo):
         """
         Save a token_info dictionary object to the cache and return None.
         """
@@ -42,8 +45,8 @@ class CacheFileHandler(CacheHandler):
     """
 
     def __init__(self,
-                 cache_path=None,
-                 username=None):
+                 cache_path: Optional[str] = None,
+                 username: Optional[str] = None):
         """
         Parameters:
              * cache_path: May be supplied, will otherwise be generated
@@ -61,7 +64,7 @@ def __init__(self,
                 cache_path += "-" + str(username)
             self.cache_path = cache_path
 
-    def get_cached_token(self):
+    def get_cached_token(self) -> Optional[TokenInfo]:
         token_info = None
 
         try:
@@ -78,7 +81,7 @@ def get_cached_token(self):
 
         return token_info
 
-    def save_token_to_cache(self, token_info):
+    def save_token_to_cache(self, token_info: TokenInfo):
         try:
             f = open(self.cache_path, "w")
             f.write(json.dumps(token_info))
@@ -95,15 +98,15 @@ class MemoryCacheHandler(CacheHandler):
     instance is freed.
     """
 
-    def __init__(self, token_info=None):
+    def __init__(self, token_info: Optional[TokenInfo] = None):
         """
         Parameters:
             * token_info: The token info to store in memory. Can be None.
         """
         self.token_info = token_info
 
-    def get_cached_token(self):
+    def get_cached_token(self) -> Optional[TokenInfo]:
         return self.token_info
 
-    def save_token_to_cache(self, token_info):
+    def save_token_to_cache(self, token_info: TokenInfo):
         self.token_info = token_info