Merge pull request #12 from ddelange/patch-1

Add B902: blind except Exception: statement

README.rst

@@ -1,7 +1,9 @@
 flake8-blind-except
 ===================
 
-A flake8 extension that checks for blind, catch-all ``except:`` statements.
+A flake8 extension that checks for blind, catch-all ``except:`` and ``except Exception:`` statements.
+
+As of `pycodestyle 2.1.0 <https://github.com/PyCQA/pycodestyle/commit/543f12b06592c53e2e60edc4846ee02ab9550e8b/>`_, "E722 do not use bare except, specify exception instead" is built-in. However, bare ``Exception`` and ``BaseException`` are still allowed. This extension flags them as `B902`.
 
 Using ``except`` without explicitly specifying which exceptions to catch is generally considered bad practice, since it catches system signals like ``SIGINT``. You probably want to handle system interrupts differently than exceptions occuring in your code.
 
@@ -50,17 +52,30 @@ When a blind except is found, ``flake8`` will output::
 
     B901 blind except: statement
 
+or::
+
+    B902 blind except Exception: statement
+
 Contributing
 ------------
 
 I'm not working on Python these days, so probably won't be making updates anytime soon. PRs are welcome though!
 
+Testing
+-------
+
+Tests can be run with ``pytest --doctest-modules flake8_blind_except.py``.
+
 Changes
-------
+-------
+
+0.2.0 - 2021-01-07
+``````````````````
+* B902 error added for cases where a blind ``Exception`` is caught.
 
 0.1.1 - 2016-06-27
 ``````````````````
-* ``pep8`` was renamed to ``pycodestyle`` in its 2.0 release. Compatibility update for this change
+* ``pep8`` was renamed to ``pycodestyle`` in its 2.0 release. Compatibility update for this change.
 
 0.1.0 - 2014-02-07
 ``````````````````
@@ -69,4 +84,4 @@ Changes
 Notes
 -----
 
-I've tested this package with flake8 2.6.2 and Python 2.7.3. It is untested (but likely compatible) with other software versions.
+I've tested this package with flake8 2.6.2 + Python 2.7.3 and flake8 3.7.9 + Python 3.7.5.

flake8_blind_except.py

@@ -1,21 +1,41 @@
-
 try:
     import pycodestyle
 except ImportError:
     import pep8 as pycodestyle
 import re
 
-__version__ = '0.1.1'
-
-BLIND_EXCEPT_REGEX = re.compile(r'(except:)')  # noqa
+__version__ = '0.2.0'
 
+BLIND_EXCEPT_REGEX = re.compile(r'(^[ \t]*except(.*\b(Base)?Exception\b.*)?:)')  # noqa
 
 def check_blind_except(physical_line):
+    """Check for blind except statements.
+
+    >>> check_blind_except('except:')
+    (0, 'B901 blind except: statement')
+    >>> check_blind_except('except Exception:')
+    (0, 'B902 blind except Exception: statement')
+    >>> check_blind_except('except  Exception as exc:')
+    (0, 'B902 blind except Exception: statement')
+    >>> check_blind_except('except ValueError, Exception as exc:')
+    (0, 'B902 blind except Exception: statement')
+    >>> check_blind_except('except Exception, ValueError as exc:')
+    (0, 'B902 blind except Exception: statement')
+    >>> check_blind_except('except BaseException as exc:')
+    (0, 'B902 blind except Exception: statement')
+    >>> check_blind_except('except GoodException as exc:  # except:')
+    >>> check_blind_except('except ExceptionGood as exc:')
+    >>> check_blind_except('except Exception')  # only trigger with trailing colon
+    >>> check_blind_except('some code containing except: in string')
+    """
     if pycodestyle.noqa(physical_line):
         return
     match = BLIND_EXCEPT_REGEX.search(physical_line)
     if match:
-        return match.start(), 'B901 blind except: statement'
+        if match.group(2) is None:
+            return match.start(), 'B901 blind except: statement'
+        else:
+            return match.start(), 'B902 blind except Exception: statement'
 
 check_blind_except.name = 'flake8-blind-except'
 check_blind_except.version = __version__