Merge pull request #1044 from praw-dev/submission_random

Return None from subreddit.random when necessary

CHANGES.rst

@@ -22,6 +22,12 @@ Unreleased
   parameter ``timeout``. Default timeout has been raised from 2 seconds to
   10 seconds.
 
+**Fixed**
+
+* :meth:`.Subreddit.random` returns ``None`` instead of raising
+  :class:`.ClientException` when the subreddit does not support generating
+  random submissions.
+
 **Other**
 
 * Bumped minimum prawcore version to 1.0.1.

praw/models/reddit/subreddit.py

@@ -527,15 +527,22 @@ def _upload_media(self, media_path):
         return upload_url + "/" + upload_data["key"]
 
     def random(self):
-        """Return a random Submission."""
+        """Return a random Submission.
+
+        Returns ``None`` on subreddits that do not support the random feature.
+        One example, at the time of writing, is /r/wallpapers.
+        """
         url = API_PATH["subreddit_random"].format(subreddit=self)
         try:
             self._reddit.get(url, params={"unique": self._reddit._next_unique})
         except Redirect as redirect:
             path = redirect.path
-        return self._submission_class(
-            self._reddit, url=urljoin(self._reddit.config.reddit_url, path)
-        )
+        try:
+            return self._submission_class(
+                self._reddit, url=urljoin(self._reddit.config.reddit_url, path)
+            )
+        except ClientException:
+            return None
 
     def rules(self):
         """Return rules for the subreddit.

pre_push.py

@@ -31,7 +31,7 @@ def main():
     """Entry point to pre_push.py."""
     success = True
     success &= do_process(["black *.py docs praw tests"], shell=True)
-    success &= do_process(["flake8", "--exclude=.eggs,docs,.tox"])
+    success &= do_process(["flake8", "--exclude=.eggs,build,dist,docs,.tox"])
     success &= do_process(["pydocstyle", "praw"])
     # success &= do_process(["pylint", "--rcfile=.pylintrc", "praw"])
 

pyproject.toml

@@ -1,2 +1,3 @@
 [tool.black]
+exclude = '/(\.eggs|\.git|\.hg|\.mypy_cache|\.nox|\.tox|\.venv|_build|buck-out|build|dist)/'
 line-length = 79

tests/integration/cassettes/TestSubreddit.test_random__returns_none.json

@@ -0,0 +1,220 @@
+{
+  "http_interactions": [
+    {
+      "recorded_at": "2019-03-09T18:26:01",
+      "request": {
+        "body": {
+          "encoding": "utf-8",
+          "string": "grant_type=client_credentials"
+        },
+        "headers": {
+          "Accept": [
+            "*/*"
+          ],
+          "Accept-Encoding": [
+            "identity"
+          ],
+          "Authorization": [
+            "Basic <BASIC_AUTH>"
+          ],
+          "Connection": [
+            "keep-alive"
+          ],
+          "Content-Length": [
+            "29"
+          ],
+          "Content-Type": [
+            "application/x-www-form-urlencoded"
+          ],
+          "User-Agent": [
+            "<USER_AGENT> PRAW/6.1.2.dev0 prawcore/1.0.1"
+          ]
+        },
+        "method": "POST",
+        "uri": "https://www.reddit.com/api/v1/access_token"
+      },
+      "response": {
+        "body": {
+          "encoding": "UTF-8",
+          "string": "{\"access_token\": \"<ACCESS_TOKEN>\", \"token_type\": \"bearer\", \"expires_in\": 3600, \"scope\": \"*\"}"
+        },
+        "headers": {
+          "Accept-Ranges": [
+            "bytes"
+          ],
+          "Connection": [
+            "keep-alive"
+          ],
+          "Content-Length": [
+            "106"
+          ],
+          "Content-Type": [
+            "application/json; charset=UTF-8"
+          ],
+          "Date": [
+            "Sat, 09 Mar 2019 18:26:03 GMT"
+          ],
+          "Server": [
+            "snooserv"
+          ],
+          "Set-Cookie": [
+            "edgebucket=GwXc0wbGP8qmtmR16B; Domain=reddit.com; Max-Age=63071999; Path=/;  secure"
+          ],
+          "Strict-Transport-Security": [
+            "max-age=15552000; includeSubDomains; preload"
+          ],
+          "Via": [
+            "1.1 varnish"
+          ],
+          "X-Cache": [
+            "MISS"
+          ],
+          "X-Cache-Hits": [
+            "0"
+          ],
+          "X-Moose": [
+            "majestic"
+          ],
+          "X-Served-By": [
+            "cache-bur17520-BUR"
+          ],
+          "X-Timer": [
+            "S1552155963.947519,VS0,VE334"
+          ],
+          "cache-control": [
+            "max-age=0, must-revalidate"
+          ],
+          "x-content-type-options": [
+            "nosniff"
+          ],
+          "x-frame-options": [
+            "SAMEORIGIN"
+          ],
+          "x-reddit-loid": [
+            "00000000003dkbrpbb.2.1552155963235.Z0FBQUFBQmNoQVU3UElPYXZKVU8wRWVPN0w0RXVzV3hWNWRTRFpIRnBuZm9jeFEtWlZ5V25BZEt5d3EtQXoxSkZScnJhRHVjS2RHcVhURjJVMTF5ZVVVYms0RlpSVEFnUjZ5QU5aWUdsUHE0QW9kSXRDVEFtOUhlVC02NVFLbGN4Qk94RkdmakxScl8"
+          ],
+          "x-xss-protection": [
+            "1; mode=block"
+          ]
+        },
+        "status": {
+          "code": 200,
+          "message": "OK"
+        },
+        "url": "https://www.reddit.com/api/v1/access_token"
+      }
+    },
+    {
+      "recorded_at": "2019-03-09T18:26:01",
+      "request": {
+        "body": {
+          "encoding": "utf-8",
+          "string": ""
+        },
+        "headers": {
+          "Accept": [
+            "*/*"
+          ],
+          "Accept-Encoding": [
+            "identity"
+          ],
+          "Authorization": [
+            "bearer <ACCESS_TOKEN>"
+          ],
+          "Connection": [
+            "keep-alive"
+          ],
+          "Cookie": [
+            "edgebucket=GwXc0wbGP8qmtmR16B"
+          ],
+          "User-Agent": [
+            "<USER_AGENT> PRAW/6.1.2.dev0 prawcore/1.0.1"
+          ]
+        },
+        "method": "GET",
+        "uri": "https://oauth.reddit.com/r/wallpapers/random/?unique=0&raw_json=1"
+      },
+      "response": {
+        "body": {
+          "encoding": "UTF-8",
+          "string": ""
+        },
+        "headers": {
+          "Accept-Ranges": [
+            "bytes"
+          ],
+          "Connection": [
+            "keep-alive"
+          ],
+          "Content-Length": [
+            "0"
+          ],
+          "Content-Type": [
+            "application/json; charset=UTF-8"
+          ],
+          "Date": [
+            "Sat, 09 Mar 2019 18:26:03 GMT"
+          ],
+          "Server": [
+            "snooserv"
+          ],
+          "Strict-Transport-Security": [
+            "max-age=15552000; includeSubDomains; preload"
+          ],
+          "Via": [
+            "1.1 varnish"
+          ],
+          "X-Cache": [
+            "MISS"
+          ],
+          "X-Cache-Hits": [
+            "0"
+          ],
+          "X-Moose": [
+            "majestic"
+          ],
+          "X-Served-By": [
+            "cache-bur17528-BUR"
+          ],
+          "X-Timer": [
+            "S1552155963.475956,VS0,VE211"
+          ],
+          "access-control-allow-origin": [
+            "*"
+          ],
+          "access-control-expose-headers": [
+            "X-Moose"
+          ],
+          "cache-control": [
+            "max-age=0, must-revalidate"
+          ],
+          "location": [
+            "https://www.reddit.com/r/wallpapers/.json?utm_campaign=redirect&utm_medium=desktop&utm_source=reddit&utm_name=random_link"
+          ],
+          "set-cookie": [
+            "loid=00000000003dkbrpbb.2.1552155963235.Z0FBQUFBQmNoQVU3RzBWcURXYXBNTzdCU0FEelAyaXc0OHpmTm5vdFh2dUNyYmVHNU4yV0U0WHJSY2pxMTRfT09RMEstT1lRRS1mWmkzVE42aXFEU00xSTdaYTE3X3hDZEttSlh1TnJrVzFnRUdfc0pYcjhVdnB1T3hkYjFTYmJtN0h6ZGc1YnFLUUY; Domain=reddit.com; Max-Age=63071999; Path=/; expires=Mon, 08-Mar-2021 18:26:03 GMT; secure",
+            "session_tracker=ES9DTLwanxM1RT5ULY.0.1552155963543.Z0FBQUFBQmNoQVU3WWwyUXpHMDZqTW5XUG9hdDR1aGJhcmplVkNyT18xQ0F2WlNydFZWeVlmNjdVYUhfSHBuem52eVAzZ3RWcURRMnpHNC1uODhYN1RmeTZSXzRlNFFlQmNHUG1HOVhna2FjZWNVQjZsdW1tRVd2UUFZZjF0ZjJYRVpFcWJlY0FQVGI; Domain=reddit.com; Max-Age=7199; Path=/; expires=Sat, 09-Mar-2019 20:26:03 GMT; secure"
+          ],
+          "x-content-type-options": [
+            "nosniff"
+          ],
+          "x-frame-options": [
+            "SAMEORIGIN"
+          ],
+          "x-ua-compatible": [
+            "IE=edge"
+          ],
+          "x-xss-protection": [
+            "1; mode=block"
+          ]
+        },
+        "status": {
+          "code": 302,
+          "message": "Found"
+        },
+        "url": "https://oauth.reddit.com/r/wallpapers/random/?unique=0&raw_json=1"
+      }
+    }
+  ],
+  "recorded_with": "betamax/0.8.1"
+}

tests/integration/models/reddit/test_subreddit.py

@@ -133,7 +133,14 @@ def test_random(self):
                 subreddit.random(),
                 subreddit.random(),
             ]
-            assert len(submissions) == len(set(submissions))
+        assert len(submissions) == len(set(submissions))
+
+    def test_random__returns_none(self):
+        with self.recorder.use_cassette(
+            "TestSubreddit.test_random__returns_none"
+        ):
+            subreddit = self.reddit.subreddit("wallpapers")
+            assert subreddit.random() is None
 
     def test_rules(self):
         with self.recorder.use_cassette("TestSubreddit.test_rules"):