Added support for including the filename in IOErrors and OSErrors that
involve a filesystem path. To that end:
- Changed IOError to EnvironmentError and added a hack which checks
for arg of len 3. When constructed with a 3-tuple, the third item
is the filename and this is squirreled away in the `filename'
attribute. However, for in-place unpacking backwards
compatibility, self.args still only gets the first two items. Added
a __str__() which prints the filename if it is given.
- IOError now inherits from EnvironmentError
- New class OSError which also inherits from EnvironmentError and is
used by the posix module.
diff --git a/Lib/exceptions.py b/Lib/exceptions.py
index ba63be6..9eba588 100644
--- a/Lib/exceptions.py
+++ b/Lib/exceptions.py
@@ -80,15 +80,44 @@
def __str__(self):
return str(self.msg)
-class IOError(StandardError):
+class EnvironmentError(StandardError):
+ """Base class for exceptions that occur outside the Python system.
+ Primarily used as a base class for OSError and IOError."""
def __init__(self, *args):
self.args = args
self.errno = None
self.strerror = None
+ self.filename = None
+ if len(args) == 3:
+ # open() errors give third argument which is the filename. BUT,
+ # so common in-place unpacking doesn't break, e.g.:
+ #
+ # except IOError, (errno, strerror):
+ #
+ # we hack args so that it only contains two items. This also
+ # means we need our own __str__() which prints out the filename
+ # when it was supplied.
+ self.errno, self.strerror, self.filename = args
+ self.args = args[0:2]
if len(args) == 2:
# common case: PyErr_SetFromErrno()
- self.errno = args[0]
- self.strerror = args[1]
+ self.errno, self.strerror = args
+
+ def __str__(self):
+ if self.filename:
+ return '[Errno %d] %s: %s' % (self.errno, self.strerror,
+ self.filename)
+ elif self.errno and self.strerror:
+ return '[Errno %d] %s' % (self.errno, self.strerror)
+ else:
+ return StandardError.__str__(self)
+
+class IOError(EnvironmentError):
+ pass
+
+class OSError(EnvironmentError):
+ """Used by the posix module."""
+ pass
class RuntimeError(StandardError):
pass