Merge pull request #44 from hf-kklein/obey_pylint

Obey Pylint

Author: lbalmaceda

00-Starter-Seed/server.py

@@ -22,13 +22,22 @@
 
 # Format error response and append status code.
 class AuthError(Exception):
+    """
+    An AuthError is raised whenever the authentication failed.
+    """
     def __init__(self, error, status_code):
+        super().__init__()
         self.error = error
         self.status_code = status_code
 
 
 @APP.errorhandler(AuthError)
 def handle_auth_error(ex):
+    """
+    serializes the given AuthError as json and sets the response status code accordingly.
+    :param ex: an auth error
+    :return: json serialized ex response
+    """
     response = jsonify(ex.error)
     response.status_code = ex.status_code
     return response
@@ -50,10 +59,10 @@ def get_token_auth_header():
                         "description":
                             "Authorization header must start with"
                             " Bearer"}, 401)
-    elif len(parts) == 1:
+    if len(parts) == 1:
         raise AuthError({"code": "invalid_header",
                         "description": "Token not found"}, 401)
-    elif len(parts) > 2:
+    if len(parts) > 2:
         raise AuthError({"code": "invalid_header",
                         "description":
                             "Authorization header must be"
@@ -78,21 +87,21 @@ def requires_scope(required_scope):
     return False
 
 
-def requires_auth(f):
+def requires_auth(func):
     """Determines if the access token is valid
     """
-    @wraps(f)
+    @wraps(func)
     def decorated(*args, **kwargs):
         token = get_token_auth_header()
         jsonurl = urlopen("https://"+AUTH0_DOMAIN+"/.well-known/jwks.json")
         jwks = json.loads(jsonurl.read())
         try:
             unverified_header = jwt.get_unverified_header(token)
-        except jwt.JWTError:
+        except jwt.JWTError as jwt_error:
             raise AuthError({"code": "invalid_header",
                             "description":
                                 "Invalid header. "
-                                "Use an RS256 signed JWT Access Token"}, 401)
+                                "Use an RS256 signed JWT Access Token"}, 401) from jwt_error
         if unverified_header["alg"] == "HS256":
             raise AuthError({"code": "invalid_header",
                             "description":
@@ -117,22 +126,22 @@ def decorated(*args, **kwargs):
                     audience=API_IDENTIFIER,
                     issuer="https://"+AUTH0_DOMAIN+"/"
                 )
-            except jwt.ExpiredSignatureError:
+            except jwt.ExpiredSignatureError as expired_sign_error:
                 raise AuthError({"code": "token_expired",
-                                "description": "token is expired"}, 401)
-            except jwt.JWTClaimsError:
+                                "description": "token is expired"}, 401) from expired_sign_error
+            except jwt.JWTClaimsError as jwt_claims_error:
                 raise AuthError({"code": "invalid_claims",
                                 "description":
                                     "incorrect claims,"
-                                    " please check the audience and issuer"}, 401)
-            except Exception:
+                                    " please check the audience and issuer"}, 401) from jwt_claims_error
+            except Exception as exc:
                 raise AuthError({"code": "invalid_header",
                                 "description":
                                     "Unable to parse authentication"
-                                    " token."}, 401)
+                                    " token."}, 401) from exc
 
             _request_ctx_stack.top.current_user = payload
-            return f(*args, **kwargs)
+            return func(*args, **kwargs)
         raise AuthError({"code": "invalid_header",
                         "description": "Unable to find appropriate key"}, 401)
     return decorated