Fix a number of flake8 errors

Broadly three things here:

* disable W504 which seems a bit whacko
* remove a bunch of `as e` expressions from exception handlers that don't use
  them
* use `r""` for strings which include backslashes

Also, we don't use pep8 any more, so we can get rid of the duplicate config
there.

6 files changed, 6 insertions, 6 deletions

diff --git a/synapse/config/repository.py b/synapse/config/repository.py

index fc909c1fac..06c62ab62c 100644
--- a/synapse/config/repository.py
+++ b/synapse/config/repository.py
@@ -178,7 +178,7 @@ class ContentRepositoryConfig(Config):
     def default_config(self, **kwargs):
         media_store = self.default_path("media_store")
         uploads_path = self.default_path("uploads")
-        return """
+        return r"""
         # Directory where uploaded images and attachments are stored.
         media_store_path: "%(media_store)s"
 
diff --git a/synapse/crypto/keyclient.py b/synapse/crypto/keyclient.py

index 57d4665e84..080c81f14b 100644
--- a/synapse/crypto/keyclient.py
+++ b/synapse/crypto/keyclient.py
@@ -55,7 +55,7 @@ def fetch_server_key(server_name, tls_client_options_factory, path=KEY_API_V1):
                 raise IOError("Cannot get key for %r" % server_name)
         except (ConnectError, DomainError) as e:
             logger.warn("Error getting key for %r: %s", server_name, e)
-        except Exception as e:
+        except Exception:
             logger.exception("Error getting key for %r", server_name)
     raise IOError("Cannot get key for %r" % server_name)
 
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py

index 4efe95faa4..af0107a46e 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -800,7 +800,7 @@ class FederationHandlerRegistry(object):
             yield handler(origin, content)
         except SynapseError as e:
             logger.info("Failed to handle edu %r: %r", edu_type, e)
-        except Exception as e:
+        except Exception:
             logger.exception("Failed to handle edu %r", edu_type)
 
     def on_query(self, query_type, args):
diff --git a/synapse/rest/client/v2_alpha/auth.py b/synapse/rest/client/v2_alpha/auth.py

index bd8b5f4afa..693b303881 100644
--- a/synapse/rest/client/v2_alpha/auth.py
+++ b/synapse/rest/client/v2_alpha/auth.py
@@ -99,7 +99,7 @@ class AuthRestServlet(RestServlet):
     cannot be handled in the normal flow (with requests to the same endpoint).
     Current use is for web fallback auth.
     """
-    PATTERNS = client_v2_patterns("/auth/(?P<stagetype>[\w\.]*)/fallback/web")
+    PATTERNS = client_v2_patterns(r"/auth/(?P<stagetype>[\w\.]*)/fallback/web")
 
     def __init__(self, hs):
         super(AuthRestServlet, self).__init__()
diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py

index 8c892ff187..1a7bfd6b56 100644
--- a/synapse/rest/media/v1/preview_url_resource.py
+++ b/synapse/rest/media/v1/preview_url_resource.py
@@ -674,7 +674,7 @@ def summarize_paragraphs(text_nodes, min_size=200, max_size=500):
         # This splits the paragraph into words, but keeping the
         # (preceeding) whitespace intact so we can easily concat
         # words back together.
-        for match in re.finditer("\s*\S+", description):
+        for match in re.finditer(r"\s*\S+", description):
             word = match.group()
 
             # Keep adding words while the total length is less than
diff --git a/synapse/storage/registration.py b/synapse/storage/registration.py

index 26b429e307..2dd14aba1c 100644
--- a/synapse/storage/registration.py
+++ b/synapse/storage/registration.py
@@ -567,7 +567,7 @@ class RegistrationStore(RegistrationWorkerStore,
         def _find_next_generated_user_id(txn):
             txn.execute("SELECT name FROM users")
 
-            regex = re.compile("^@(\d+):")
+            regex = re.compile(r"^@(\d+):")
 
             found = set()