# File: exceptions-example-1.py

# python imports this module by itself, so the following
# line isn't really needed
# import exceptions

class HTTPError(Exception):
    # indicates an HTTP protocol error
    def __init__(self, url, errcode, errmsg):
        self.url = url
        self.errcode = errcode
        self.errmsg = errmsg
    def __str__(self):
        return (
            "<HTTPError for %s: %s %s>" %
            (self.url, self.errcode, self.errmsg)
            )

try:
    raise HTTPError("http://www.python.org/foo", 200, "Not Found")
except HTTPError, error:
    print "url", "=>", error.url
    print "errcode", "=>", error.errcode
    print "errmsg", "=>", error.errmsg
    raise # reraise exception

## $ python exceptions-example-1.py
## url => http://www.python.org/foo
## errcode => 200
## errmsg => Not Found
## Traceback (innermost last):
##   File "exceptions-example-1", line 16, in ?
## HTTPError: <HTTPError for http://www.python.org/foo: 200 Not Found>