Fix pylint warning raise-missing-from

docs/contributors/fetch.py

@@ -207,12 +207,12 @@ def fetch(url: str, params: Optional[Dict[str, str]] = None) -> UserInfo:
                     xrate_limit_reset = int(exc.response.headers['X-RateLimit-Reset'])
                     wait = xrate_limit_reset - now
                     if wait > 20:
-                        raise FinishedForNow()
+                        raise FinishedForNow() from exc
                     debug(' !', 'Waiting', wait, 'seconds before another try ...')
                     sleep(wait)
                 continue
             return req.json()
-    assert ValueError('Rate limit exceeded')
+    raise ValueError('Rate limit exceeded')
 
 
 def new_person(**kwargs: str) -> Person:

httpie/cli/argtypes.py

@@ -219,8 +219,8 @@ def parse_format_options(s: str, defaults: Optional[dict]) -> dict:
         try:
             path, value = option.lower().split(':')
             section, key = path.split('.')
-        except ValueError:
-            raise argparse.ArgumentTypeError(f'invalid option {option!r}')
+        except ValueError as exc:
+            raise argparse.ArgumentTypeError(f'invalid option {option!r}') from exc
 
         if value in value_map:
             parsed_value = value_map[value]
@@ -235,9 +235,8 @@ def parse_format_options(s: str, defaults: Optional[dict]) -> dict:
         else:
             try:
                 default_value = defaults[section][key]
-            except KeyError:
-                raise argparse.ArgumentTypeError(
-                    f'invalid key {path!r}')
+            except KeyError as exc:
+                raise argparse.ArgumentTypeError(f'invalid key {path!r}') from exc
 
             default_type, parsed_type = type(default_value), type(parsed_value)
             if parsed_type is not default_type:
@@ -246,7 +245,7 @@ def parse_format_options(s: str, defaults: Optional[dict]) -> dict:
                     f' {value!r} in {option!r}'
                     f' (expected {default_type.__name__}'
                     f' got {parsed_type.__name__})'
-                )
+                ) from exc
 
         options[section][key] = parsed_value
 
@@ -262,9 +261,8 @@ PARSED_DEFAULT_FORMAT_OPTIONS = parse_format_options(
 def response_charset_type(encoding: str) -> str:
     try:
         ''.encode(encoding)
-    except LookupError:
-        raise argparse.ArgumentTypeError(
-            f'{encoding!r} is not a supported encoding')
+    except LookupError as exc:
+        raise argparse.ArgumentTypeError(f'{encoding!r} is not a supported encoding') from exc
     return encoding
 
 

httpie/cli/requestitems.py

@@ -154,7 +154,7 @@ def process_file_upload_arg(arg: KeyValueArg) -> Tuple[str, IO, str]:
     try:
         f = open(os.path.expanduser(filename), 'rb')
     except OSError as e:
-        raise ParseError(f'{arg.orig!r}: {e}')
+        raise ParseError(f'{arg.orig!r}: {e}') from e
     return (
         os.path.basename(filename),
         f,
@@ -215,16 +215,16 @@ def load_text_file(item: KeyValueArg) -> str:
         with open(os.path.expanduser(path), 'rb') as f:
             return f.read().decode()
     except OSError as e:
-        raise ParseError(f'{item.orig!r}: {e}')
-    except UnicodeDecodeError:
+        raise ParseError(f'{item.orig!r}: {e}') from e
+    except UnicodeDecodeError as exc:
         raise ParseError(
             f'{item.orig!r}: cannot embed the content of {item.value!r},'
             ' not a UTF-8 or ASCII-encoded text file'
-        )
+        ) from exc
 
 
 def load_json(arg: KeyValueArg, contents: str) -> JSONType:
     try:
         return load_json_preserve_order_and_dupe_keys(contents)
     except ValueError as e:
-        raise ParseError(f'{arg.orig!r}: {e}')
+        raise ParseError(f'{arg.orig!r}: {e}') from e

httpie/config.py

@@ -68,11 +68,9 @@ def read_raw_config(config_type: str, path: Path) -> Dict[str, Any]:
             try:
                 return json.load(f)
             except ValueError as e:
-                raise ConfigFileError(
-                    f'invalid {config_type} file: {e} [{path}]'
-                )
+                raise ConfigFileError(f'invalid {config_type} file: {e} [{path}]')
     except FileNotFoundError:
-        pass
+        raise ConfigFileError(f'cannot read {config_type} file: {path} not found')
     except OSError as e:
         raise ConfigFileError(f'cannot read {config_type} file: {e}')
 

httpie/output/utils.py

@@ -13,15 +13,15 @@ def load_prefixed_json(data: str) -> Tuple[str, json.JSONDecoder]:
     # First, the full data.
     try:
         return '', load_json_preserve_order_and_dupe_keys(data)
-    except ValueError:
-        pass
+    except ValueError as exc:
+        raise ValueError('Invalid JSON') from exc
 
     # Then, try to find the start of the actual body.
     data_prefix, body = parse_prefixed_json(data)
     try:
         return data_prefix, load_json_preserve_order_and_dupe_keys(body)
-    except ValueError:
-        raise ValueError('Invalid JSON')
+    except ValueError as exc:
+        raise ValueError('Invalid JSON') from exc
 
 
 def parse_prefixed_json(data: str) -> Tuple[str, str]: