Python code modernization, 5/n (#1165)

* Address raise-missing-from.

* Address simplifiable-if-expression.

* Address unnecessary-dunder-call.

* Address unnecessary-pass.

* Address use-list-literal.

* Address unused-variable.

* Address use-dict-literal.

plugins/module_utils/_api/api/client.py

@@ -227,18 +227,20 @@ class APIClient(_Session, DaemonApiMixin):
         try:
             version_result = self.version(api_version=False)
         except Exception as e:
-            raise DockerException(f"Error while fetching server API version: {e}")
+            raise DockerException(
+                f"Error while fetching server API version: {e}"
+            ) from e
 
         try:
             return version_result["ApiVersion"]
         except KeyError:
             raise DockerException(
                 'Invalid response from docker daemon: key "ApiVersion" is missing.'
-            )
+            ) from None
         except Exception as e:
             raise DockerException(
                 f"Error while fetching server API version: {e}. Response seems to be broken."
-            )
+            ) from e
 
     def _set_request_timeout(self, kwargs):
         """Prepare the kwargs for an HTTP request by inserting the timeout

plugins/module_utils/_api/auth.py

@@ -370,7 +370,6 @@ def _load_legacy_config(config_file):
         }
     except Exception as e:  # pylint: disable=broad-exception-caught
         log.debug(e)
-        pass
 
     log.debug("All parsing attempts failed - returning empty config")
     return {}

plugins/module_utils/_api/context/context.py

@@ -106,7 +106,7 @@ class Context:
             self.tls_cfg[name] = tls_cfg
 
     def inspect(self):
-        return self.__call__()
+        return self()
 
     @classmethod
     def load_context(cls, name):

plugins/module_utils/_api/tls.py

@@ -71,7 +71,7 @@ class TLSConfig:
             except ValueError:
                 raise errors.TLSParameterError(
                     "client_cert must be a tuple of (client certificate, key file)"
-                )
+                ) from None
 
             if not (tls_cert and tls_key) or (
                 not os.path.isfile(tls_cert) or not os.path.isfile(tls_key)

plugins/module_utils/_api/transport/npipeconn.py

@@ -52,16 +52,16 @@ class NpipeHTTPConnectionPool(urllib3.connectionpool.HTTPConnectionPool):
         try:
             conn = self.pool.get(block=self.block, timeout=timeout)
 
-        except AttributeError:  # self.pool is None
-            raise urllib3.exceptions.ClosedPoolError(self, "Pool is closed.")
+        except AttributeError as exc:  # self.pool is None
+            raise urllib3.exceptions.ClosedPoolError(self, "Pool is closed.") from exc
 
-        except Empty:
+        except Empty as exc:
             if self.block:
                 raise urllib3.exceptions.EmptyPoolError(
                     self,
                     "Pool reached maximum size and no more connections are allowed.",
-                )
-            pass  # Oh well, we'll create a new connection then
+                ) from exc
+            # Oh well, we'll create a new connection then
 
         return conn or self._new_conn()
 

plugins/module_utils/_api/transport/npipesocket.py

@@ -141,7 +141,7 @@ class NpipeSocket:
 
     @check_closed
     def recv(self, bufsize, flags=0):
-        err, data = win32file.ReadFile(self._handle, bufsize)
+        dummy_err, data = win32file.ReadFile(self._handle, bufsize)
         return data
 
     @check_closed
@@ -163,7 +163,7 @@ class NpipeSocket:
         try:
             overlapped = pywintypes.OVERLAPPED()
             overlapped.hEvent = event
-            err, data = win32file.ReadFile(
+            dummy_err, dummy_data = win32file.ReadFile(
                 self._handle, readbuf[:nbytes] if nbytes else readbuf, overlapped
             )
             wait_result = win32event.WaitForSingleObject(event, self._timeout)

plugins/module_utils/_api/transport/sshconn.py

@@ -159,16 +159,16 @@ class SSHConnectionPool(urllib3.connectionpool.HTTPConnectionPool):
         try:
             conn = self.pool.get(block=self.block, timeout=timeout)
 
-        except AttributeError:  # self.pool is None
-            raise urllib3.exceptions.ClosedPoolError(self, "Pool is closed.")
+        except AttributeError as exc:  # self.pool is None
+            raise urllib3.exceptions.ClosedPoolError(self, "Pool is closed.") from exc
 
-        except Empty:
+        except Empty as exc:
             if self.block:
                 raise urllib3.exceptions.EmptyPoolError(
                     self,
                     "Pool reached maximum size and no more connections are allowed.",
-                )
-            pass  # Oh well, we'll create a new connection then
+                ) from exc
+            # Oh well, we'll create a new connection then
 
         return conn or self._new_conn()
 

plugins/module_utils/_api/types/daemon.py

@@ -39,10 +39,10 @@ class CancellableStream:
     def __next__(self):
         try:
             return next(self._stream)
-        except urllib3.exceptions.ProtocolError:
-            raise StopIteration
-        except socket.error:
-            raise StopIteration
+        except urllib3.exceptions.ProtocolError as exc:
+            raise StopIteration from exc
+        except socket.error as exc:
+            raise StopIteration from exc
 
     next = __next__
 

plugins/module_utils/_api/utils/build.py

@@ -107,8 +107,8 @@ def create_archive(root, files=None, fileobj=None, gzip=False, extra_files=None)
             try:
                 with open(full_path, "rb") as f:
                     t.addfile(i, f)
-            except IOError:
-                raise IOError(f"Can not read file in context: {full_path}")
+            except IOError as exc:
+                raise IOError(f"Can not read file in context: {full_path}") from exc
         else:
             # Directories, FIFOs, symlinks... do not need to be read.
             t.addfile(i, None)

plugins/module_utils/_api/utils/json_stream.py

@@ -85,4 +85,4 @@ def split_buffer(stream, splitter=None, decoder=lambda a: a):
         try:
             yield decoder(buffered)
         except Exception as e:
-            raise StreamParseError(e)
+            raise StreamParseError(e) from e

plugins/module_utils/_api/utils/utils.py

@@ -420,10 +420,10 @@ def parse_bytes(s):
     if suffix in units or suffix.isdigit():
         try:
             digits = float(digits_part)
-        except ValueError:
+        except ValueError as exc:
             raise errors.DockerException(
                 f"Failed converting the string value for memory ({digits_part}) to an integer."
-            )
+            ) from exc
 
         # Reconvert to long for the final result
         s = int(digits * units[suffix])