why the code error?

[Tim Roberts]

lunxian at yahoo.com (lunxian) wrote:

>i'm a newbie of python. i encounter a problem in my programming.
>here is my program. when it's running, a IOError always raised.
>why? and how can i get more detail error message of the exception?

If you get rid of the try/except, the error message will give you more
information.

>import os
>import sys
>
>def Parser(filename):
>    lines = None
>    try: 
>        fsock = file("forparser.py","r",0)

I assume you meant file(filename,"r") here, but put the file name in
directly for testing.  Does "forparser.py" exist in the current directory?
Otherwise, I don't see anything wrong with this.

>        try: 
>            lines = fsock.readlines() 
>        finally: 
>            fsock.close() 
>    except IOError:
>        print IOError.__str__
>        return
>
>    for line in lines:
>        print line

I would have written all of that as:

    for line in open('filename').readlines():
        print line

but that's just personal preference.

>if __name__ == "__main__":
>    Parser("c:\forparser.py")

Backslashes have special meaning.  You need to use one of these:
    Parser("c:\\forparser.py")
    Parser(r"c:\forparser.py")
    Parser("c:/forparser.py")

Otherwise, the \f will be changed to a formfeed -- 0x0C.
--
- Tim Roberts, timr at probo.com
  Providenza & Boekelheide, Inc.