Merge pull request #478 from marshmallow-code/pylint

Minor refactors and pylint fixes

CHANGELOG.rst

@@ -10,6 +10,12 @@ Features:
   provide compatibility with ``falcon.testing`` (:pr:`477`).
   Thanks :user:`suola` for the PR.
 
+* *Backwards-incompatible*: Factorize the ``use_args`` / ``use_kwargs`` branch
+  in all parsers. When ``as_kwargs`` is ``False``, arguments are now
+  consistently appended to the arguments list by the ``use_args`` decorator.
+  Before this change, the ``PyramidParser`` would prepend the argument list on
+  each call to ``use_args``. Pyramid view functions must reverse the order of
+  their arguments. (:pr:`478`)
 
 6.0.0b8 (2020-02-16)
 ********************

src/webargs/aiohttpparser.py

@@ -101,13 +101,12 @@ async def load_json(self, req: Request, schema: Schema) -> typing.Dict:
             return core.missing
         try:
             return await req.json(loads=json.loads)
-        except json.JSONDecodeError as e:
-            if e.doc == "":
+        except json.JSONDecodeError as exc:
+            if exc.doc == "":
                 return core.missing
-            else:
-                return self._handle_invalid_json_error(e, req)
-        except UnicodeDecodeError as e:
-            return self._handle_invalid_json_error(e, req)
+            return self._handle_invalid_json_error(exc, req)
+        except UnicodeDecodeError as exc:
+            return self._handle_invalid_json_error(exc, req)
 
     def load_headers(self, req: Request, schema: Schema) -> MultiDictProxy:
         """Return headers from the request as a MultiDictProxy."""
@@ -138,7 +137,7 @@ def get_request_from_view_args(
             if isinstance(arg, web.Request):
                 req = arg
                 break
-            elif isinstance(arg, web.View):
+            if isinstance(arg, web.View):
                 req = arg.request
                 break
         if not isinstance(req, web.Request):

src/webargs/asyncparser.py

@@ -147,13 +147,10 @@ async def wrapper(*args, **kwargs):
                         error_status_code=error_status_code,
                         error_headers=error_headers,
                     )
-                    if as_kwargs:
-                        kwargs.update(parsed_args or {})
-                        return await func(*args, **kwargs)
-                    else:
-                        # Add parsed_args after other positional arguments
-                        new_args = args + (parsed_args,)
-                        return await func(*new_args, **kwargs)
+                    args, kwargs = self._update_args_kwargs(
+                        args, kwargs, parsed_args, as_kwargs
+                    )
+                    return await func(*args, **kwargs)
 
             else:
 
@@ -172,22 +169,11 @@ def wrapper(*args, **kwargs):
                         error_status_code=error_status_code,
                         error_headers=error_headers,
                     )
-                    if as_kwargs:
-                        kwargs.update(parsed_args)
-                        return func(*args, **kwargs)  # noqa: B901
-                    else:
-                        # Add parsed_args after other positional arguments
-                        new_args = args + (parsed_args,)
-                        return func(*new_args, **kwargs)
+                    args, kwargs = self._update_args_kwargs(
+                        args, kwargs, parsed_args, as_kwargs
+                    )
+                    return func(*args, **kwargs)
 
             return wrapper
 
         return decorator
-
-    def use_kwargs(self, *args, **kwargs) -> typing.Callable:
-        """Decorator that injects parsed arguments into a view function or method.
-
-        Receives the same arguments as `webargs.core.Parser.use_kwargs`.
-
-        """
-        return super().use_kwargs(*args, **kwargs)

src/webargs/bottleparser.py

@@ -45,8 +45,7 @@ def _raw_load_json(self, req):
         # see: https://github.com/bottlepy/bottle/issues/1160
         if data is None:
             return core.missing
-        else:
-            return data
+        return data
 
     def load_querystring(self, req, schema):
         """Return query params from the request as a MultiDictProxy."""

src/webargs/core.py

@@ -1,5 +1,6 @@
 import functools
 import inspect
+import typing
 import logging
 import warnings
 from collections.abc import Mapping
@@ -35,8 +36,7 @@ def _callable_or_raise(obj):
     """
     if obj and not callable(obj):
         raise ValueError("{!r} is not callable.".format(obj))
-    else:
-        return obj
+    return obj
 
 
 def is_multiple(field):
@@ -66,17 +66,17 @@ def is_json(mimetype):
     return False
 
 
-def parse_json(s, *, encoding="utf-8"):
-    if isinstance(s, bytes):
+def parse_json(string, *, encoding="utf-8"):
+    if isinstance(string, bytes):
         try:
-            s = s.decode(encoding)
-        except UnicodeDecodeError as e:
+            string = string.decode(encoding)
+        except UnicodeDecodeError as exc:
             raise json.JSONDecodeError(
-                "Bytes decoding error : {}".format(e.reason),
-                doc=str(e.object),
-                pos=e.start,
+                "Bytes decoding error : {}".format(exc.reason),
+                doc=str(exc.object),
+                pos=exc.start,
             )
-    return json.loads(s)
+    return json.loads(string)
 
 
 def _ensure_list_of_callables(obj):
@@ -291,6 +291,16 @@ def get_request_from_view_args(self, view, args, kwargs):
         """
         return None
 
+    @staticmethod
+    def _update_args_kwargs(args, kwargs, parsed_args, as_kwargs):
+        """Update args or kwargs with parsed_args depending on as_kwargs"""
+        if as_kwargs:
+            kwargs.update(parsed_args)
+        else:
+            # Add parsed_args after other positional arguments
+            args += (parsed_args,)
+        return args, kwargs
+
     def use_args(
         self,
         argmap,
@@ -350,20 +360,17 @@ def wrapper(*args, **kwargs):
                     error_status_code=error_status_code,
                     error_headers=error_headers,
                 )
-                if as_kwargs:
-                    kwargs.update(parsed_args)
-                    return func(*args, **kwargs)
-                else:
-                    # Add parsed_args after other positional arguments
-                    new_args = args + (parsed_args,)
-                    return func(*new_args, **kwargs)
+                args, kwargs = self._update_args_kwargs(
+                    args, kwargs, parsed_args, as_kwargs
+                )
+                return func(*args, **kwargs)
 
             wrapper.__wrapped__ = func
             return wrapper
 
         return decorator
 
-    def use_kwargs(self, *args, **kwargs):
+    def use_kwargs(self, *args, **kwargs) -> typing.Callable:
         """Decorator that injects parsed arguments into a view function or method
         as keyword arguments.
 
@@ -456,12 +463,12 @@ def load_json(self, req, schema):
         # code sharing amongst the built-in webargs parsers
         try:
             return self._raw_load_json(req)
-        except json.JSONDecodeError as e:
-            if e.doc == "":
+        except json.JSONDecodeError as exc:
+            if exc.doc == "":
                 return missing
-            return self._handle_invalid_json_error(e, req)
-        except UnicodeDecodeError as e:
-            return self._handle_invalid_json_error(e, req)
+            return self._handle_invalid_json_error(exc, req)
+        except UnicodeDecodeError as exc:
+            return self._handle_invalid_json_error(exc, req)
 
     def load_json_or_form(self, req, schema):
         """Load data from a request, accepting either JSON or form-encoded

src/webargs/falconparser.py

@@ -106,8 +106,7 @@ def _raw_load_json(self, req):
         body = req.stream.read(req.content_length)
         if body:
             return core.parse_json(body)
-        else:
-            return core.missing
+        return core.missing
 
     def load_headers(self, req, schema):
         """Return headers from the request."""

src/webargs/multidictproxy.py

@@ -1,8 +1,8 @@
+from collections.abc import Mapping
+
 from webargs.compat import MARSHMALLOW_VERSION_INFO
 from webargs.core import missing, is_multiple
 
-from collections.abc import Mapping
-
 
 class MultiDictProxy(Mapping):
     """
@@ -18,7 +18,8 @@ def __init__(self, multidict, schema):
         self.data = multidict
         self.multiple_keys = self._collect_multiple_keys(schema)
 
-    def _collect_multiple_keys(self, schema):
+    @staticmethod
+    def _collect_multiple_keys(schema):
         result = set()
         for name, field in schema.fields.items():
             if not is_multiple(field):
@@ -35,9 +36,9 @@ def __getitem__(self, key):
             return val
         if hasattr(self.data, "getlist"):
             return self.data.getlist(key)
-        elif hasattr(self.data, "getall"):
+        if hasattr(self.data, "getall"):
             return self.data.getall(key)
-        elif isinstance(val, (list, tuple)):
+        if isinstance(val, (list, tuple)):
             return val
         if val is None:
             return None

src/webargs/pyramidparser.py

@@ -159,11 +159,10 @@ def wrapper(obj, *args, **kwargs):
                     error_status_code=error_status_code,
                     error_headers=error_headers,
                 )
-                if as_kwargs:
-                    kwargs.update(parsed_args)
-                    return func(obj, *args, **kwargs)
-                else:
-                    return func(obj, parsed_args, *args, **kwargs)
+                args, kwargs = self._update_args_kwargs(
+                    args, kwargs, parsed_args, as_kwargs
+                )
+                return func(obj, *args, **kwargs)
 
             wrapper.__wrapped__ = func
             return wrapper

src/webargs/tornadoparser.py

@@ -46,17 +46,16 @@ def __getitem__(self, key):
             value = self.data.get(key, core.missing)
             if value is core.missing:
                 return core.missing
-            elif key in self.multiple_keys:
+            if key in self.multiple_keys:
                 return [
                     _unicode(v) if isinstance(v, (str, bytes)) else v for v in value
                 ]
-            elif value and isinstance(value, (list, tuple)):
+            if value and isinstance(value, (list, tuple)):
                 value = value[0]
 
             if isinstance(value, (str, bytes)):
                 return _unicode(value)
-            else:
-                return value
+            return value
         # based on tornado.web.RequestHandler.decode_argument
         except UnicodeDecodeError:
             raise HTTPError(400, "Invalid unicode in {}: {!r}".format(key, value[:40]))
@@ -73,10 +72,9 @@ def __getitem__(self, key):
         cookie = self.data.get(key, core.missing)
         if cookie is core.missing:
             return core.missing
-        elif key in self.multiple_keys:
+        if key in self.multiple_keys:
             return [cookie.value]
-        else:
-            return cookie.value
+        return cookie.value
 
 
 class TornadoParser(core.Parser):

tests/apps/aiohttp_app.py

@@ -1,9 +1,9 @@
 import asyncio
 
 import aiohttp
-import marshmallow as ma
-from aiohttp import web
 from aiohttp.web import json_response
+import marshmallow as ma
+
 from webargs import fields
 from webargs.aiohttpparser import parser, use_args, use_kwargs
 from webargs.core import MARSHMALLOW_VERSION_INFO, json
@@ -48,7 +48,7 @@ async def echo_json(request):
     try:
         parsed = await parser.parse(hello_args, request, location="json")
     except json.JSONDecodeError:
-        raise web.HTTPBadRequest(
+        raise aiohttp.web.HTTPBadRequest(
             body=json.dumps(["Invalid JSON."]).encode("utf-8"),
             content_type="application/json",
         )
@@ -59,7 +59,7 @@ async def echo_json_or_form(request):
     try:
         parsed = await parser.parse(hello_args, request, location="json_or_form")
     except json.JSONDecodeError:
-        raise web.HTTPBadRequest(
+        raise aiohttp.web.HTTPBadRequest(
             body=json.dumps(["Invalid JSON."]).encode("utf-8"),
             content_type="application/json",
         )
@@ -184,7 +184,7 @@ async def get(self, request, args):
         return json_response(args)
 
 
-class EchoHandlerView(web.View):
+class EchoHandlerView(aiohttp.web.View):
     @asyncio.coroutine
     @use_args(hello_args, location="query")
     def get(self, args):

tests/apps/bottle_app.py

@@ -1,10 +1,9 @@
-from webargs.core import json
 from bottle import Bottle, HTTPResponse, debug, request, response
 
 import marshmallow as ma
 from webargs import fields
 from webargs.bottleparser import parser, use_args, use_kwargs
-from webargs.core import MARSHMALLOW_VERSION_INFO
+from webargs.core import json, MARSHMALLOW_VERSION_INFO
 
 
 hello_args = {"name": fields.Str(missing="World", validate=lambda n: len(n) >= 3)}

tests/apps/django_app/echo/views.py

@@ -1,11 +1,10 @@
-from webargs.core import json
 from django.http import HttpResponse
 from django.views.generic import View
-
 import marshmallow as ma
+
 from webargs import fields
 from webargs.djangoparser import parser, use_args, use_kwargs
-from webargs.core import MARSHMALLOW_VERSION_INFO
+from webargs.core import json, MARSHMALLOW_VERSION_INFO
 
 
 hello_args = {"name": fields.Str(missing="World", validate=lambda n: len(n) >= 3)}

tests/apps/falcon_app.py

@@ -1,5 +1,6 @@
 import falcon
 import marshmallow as ma
+
 from webargs import fields
 from webargs.core import MARSHMALLOW_VERSION_INFO, json
 from webargs.falconparser import parser, use_args, use_kwargs

tests/apps/flask_app.py

@@ -1,11 +1,10 @@
-from webargs.core import json
 from flask import Flask, jsonify as J, Response, request
 from flask.views import MethodView
-
 import marshmallow as ma
+
 from webargs import fields
 from webargs.flaskparser import parser, use_args, use_kwargs
-from webargs.core import MARSHMALLOW_VERSION_INFO
+from webargs.core import json, MARSHMALLOW_VERSION_INFO
 
 
 class TestAppConfig:

tests/apps/pyramid_app.py

@@ -1,12 +1,10 @@
-from webargs.core import json
-
 from pyramid.config import Configurator
 from pyramid.httpexceptions import HTTPBadRequest
 import marshmallow as ma
 
 from webargs import fields
 from webargs.pyramidparser import parser, use_args, use_kwargs
-from webargs.core import MARSHMALLOW_VERSION_INFO
+from webargs.core import json, MARSHMALLOW_VERSION_INFO
 
 hello_args = {"name": fields.Str(missing="World", validate=lambda n: len(n) >= 3)}
 hello_multiple = {"name": fields.List(fields.Str())}