Fix new flake8 tests (#2274)

* Ignore new flake8 tests

These new exclusions include:
* E722 - bare except
* E741 - ambiguous variable name
* E742 - ambiguous class definition

* Update flake8 calls for corrected exclusions

* Revert flake8 test exclusions

* Fix instance of E742 violation

* Fix instance of E741 violation

* Replace bare except with BaseException

* Replace bare except with AttributeError

* Remove unnecessary try/except

luigi/contrib/docker_runner.py

@@ -227,7 +227,7 @@ def run(self):
                 container_name = self.name
             try:
                 message = e.message
-            except:
+            except AttributeError:
                 message = str(e)
             self.__logger.error("Container " + container_name +
                                 " exited with non zero code: " + message)

luigi/contrib/hadoop.py

@@ -850,7 +850,7 @@ def writer(self, outputs, stdout, stderr=sys.stderr):
                     # JSON is already serialized, so we put `self.serialize` in a else statement.
                     output = map(self.serialize, output)
                 print("\t".join(output), file=stdout)
-            except:
+            except BaseException:
                 print(output, file=stderr)
                 raise
 

luigi/contrib/redshift.py

@@ -687,12 +687,10 @@ def run(self):
             credentials=self._credentials())
 
         logger.info('Executing unload query from task: {name}'.format(name=self.__class__))
-        try:
-            cursor = connection.cursor()
-            cursor.execute(unload_query)
-            logger.info(cursor.statusmessage)
-        except:
-            raise
+
+        cursor = connection.cursor()
+        cursor.execute(unload_query)
+        logger.info(cursor.statusmessage)
 
         # Update marker table
         self.output().touch(connection)

luigi/contrib/s3.py

@@ -467,7 +467,7 @@ def __copy_multipart(self, pool, src_bucket, src_key, dst_bucket, dst_key, part_
             mp.complete_upload()
             return mp.key_name
 
-        except:
+        except BaseException:
             logger.info('Error during multipart s3 copy for %s/%s to %s/%s...', src_bucket, src_key, dst_bucket, dst_key)
             # cancel the copy so we don't get charged for storage consumed by copied parts
             if mp:

luigi/db_task_history.py

@@ -70,7 +70,7 @@ def _session(self, session=None):
             session = self.session_factory()
             try:
                 yield session
-            except:
+            except BaseException:
                 session.rollback()
                 raise
             else:

luigi/worker.py

@@ -404,7 +404,7 @@ def run(self):
                 response = None
                 try:
                     response = self._scheduler.ping(worker=self._worker_id)
-                except:  # httplib.BadStatusLine:
+                except BaseException:  # httplib.BadStatusLine:
                     logger.warning('Failed pinging scheduler')
 
                 # handle rpc messages

test/contrib/hdfs_test.py

@@ -145,7 +145,7 @@ def test_with_close(self):
         try:
             if self.fs.exists(testpath):
                 self.fs.remove(testpath, skip_trash=True)
-        except:
+        except BaseException:
             if self.fs.exists(self._test_dir()):
                 self.fs.remove(self._test_dir(), skip_trash=True)
 
@@ -159,7 +159,7 @@ def test_with_noclose(self):
         try:
             if self.fs.exists(testpath):
                 self.fs.remove(testpath, skip_trash=True)
-        except:
+        except BaseException:
             if self.fs.exists(self._test_dir()):
                 self.fs.remove(self._test_dir(), skip_trash=True)
 
@@ -175,7 +175,7 @@ def test_target_path_exists(self):
         try:
             if self.fs.exists(testpath):
                 self.fs.remove(testpath, skip_trash=True)
-        except:
+        except BaseException:
             if self.fs.exists(self._test_dir()):
                 self.fs.remove(self._test_dir(), skip_trash=True)
 
@@ -195,7 +195,7 @@ def test_target_path_exists_rename_fails_hadoopcli(self, remove):
         try:
             if self.fs.exists(testpath):
                 self.fs.remove(testpath, skip_trash=True)
-        except:
+        except BaseException:
             if self.fs.exists(self._test_dir()):
                 self.fs.remove(self._test_dir(), skip_trash=True)
 
@@ -214,7 +214,7 @@ def test_target_path_exists_rename_fails_snakebite(self, remove, rename):
         try:
             if self.fs.exists(testpath):
                 self.fs.remove(testpath, skip_trash=True)
-        except:
+        except BaseException:
             if self.fs.exists(self._test_dir()):
                 self.fs.remove(self._test_dir(), skip_trash=True)
 
@@ -390,7 +390,7 @@ def test_slow_exists(self):
         target = hdfs.HdfsTarget(self._test_file())
         try:
             target.remove(skip_trash=True)
-        except:
+        except BaseException:
             pass
 
         self.assertFalse(self.fs.exists(target.path))

test/decorator_test.py

@@ -133,7 +133,7 @@ def requires(self):
 
 
 @inherits(G)
-class I(luigi.Task):
+class I_task(luigi.Task):
 
     def requires(self):
         return F(**common_params(self, F))
@@ -183,7 +183,7 @@ def setUp(self):
         self.g_changed = G(param1="changing the default")
         self.h = H()
         self.h_null = H_null()
-        self.i = I()
+        self.i = I_task()
         self.k_shouldfail = K_shouldfail()
         self.k_shouldsucceed = K_shouldsucceed()
         self.k_wrongparamsorder = K_wrongparamsorder()

test/parameter_test.py

@@ -873,11 +873,11 @@ def complete(self):
     def testListWithNamespaceCli(self):
         class A(luigi.Task):
             task_namespace = 'mynamespace'
-            l = luigi.ListParameter(default=[1, 2, 3])
+            l_param = luigi.ListParameter(default=[1, 2, 3])
             expected = luigi.ListParameter()
 
             def complete(self):
-                if self.l != self.expected:
+                if self.l_param != self.expected:
                     raise ValueError
                 return True
 

test/simulate_test.py

@@ -39,7 +39,7 @@ def is_writable():
             pass
         open(fn, 'w').close()
         os.remove(fn)
-    except:
+    except BaseException:
         exists = False
 
     return unittest.skipIf(not exists, 'Can\'t write to temporary directory')