From: tim_one at email.msn.com (Tim Peters)
Date: Mon, 26 Apr 1999 00:45:32 GMT
Subject: Handling backspace chars in a string...
In-Reply-To: <37239c48.594910176@news2.bga.com>
References: <37239c48.594910176@news2.bga.com>
Message-ID: <000301be8f7e$16b89780$669e2299@tim>
Content-Length: 1038
X-UID: 1104                                                  

[Purple]
> I'm in the poistion of having to process strings with arbitrary
> numbers of backspace and newline characters in them.

Your code doesn't appear to care about newlines one way or t'other.  Do you
<wink>?

> The backspaces actually get put in the string, so I have to handle
> removing the characters that are backspaced over.
> ... [rather sprawling string + indexing code] ...
> This just looked rather messy to me -- I was curious if anyone know a
> better way?

Assuming "better" means "less messy" here, lists support appending and
deleting quite naturally and efficiently; like

def stripbs(sin):
    import string
    sout = []
    for ch in sin:
        if ch == '\b':
            del sout[-1:]  # a nop if len(sout) == 0
        else:
            sout.append(ch)
    return string.join(sout, '')

This essentially treats the input string as a sequence of opcodes for a
stack machine, where "\b" means "pop" and anything else means "push me!".

don't-use-any-indices-and-you-can't-screw-'em-up<wink>-ly y'rs  - tim






