[Python-Dev] New string method - splitquoted (original) (raw)

Dave Cinege dcinegemlists2-dated-1148418122.b868e0 at psychosis.com
Thu May 18 23:01:58 CEST 2006

On Thursday 18 May 2006 16:13, you wrote:

Dave Cinege wrote: > For example: > > s = ' Chan: 11 SNR: 22 ESSID: "Spaced Out Wifi" Enc: On'

My complaint with this example is that you are just using the wrong tool to do this job. If I was going to do this, I would've immediately jumped on the regex-press train. wifiinfo = re.match('^\s+' 'Chan:\s+(?P[0-9]+)\s+' 'SNR:\s+(?P[0-9]+)\s+' 'ESSID:\s+"(?P[^"]*)"\s+' 'Enc:\s+(?P[a-zA-Z]+)' , s)

For the 5 years of been pythoning, I've used re probably twice. I find regex to be a tool of last resort, and quite a bit of effort to get right, as regex (for me) is quite prone it giving unintended results without a good deal of thought. I don't want to have to think. That's why I use python. : )

.split() and slicing has always been python's holy grail for me, and I find it a lot easier to .replace() 'stray' chars with spaces or a delimiter and then split() that. It's easier to read and (should be) a lot quicker to process then regex. (Which I care about, as I'm also often on embedded CPU's of a few hundred MHz)

So .split works just super duper.....but I keep running in to situations where I'd like a substr to be excluded from the split'ing.

The clearest one is excluding a 'quoted' string that has whitespace. Here's another, be it, a very poor example:

s = '\t\tFrequency:2.462 GHz (Channel 11)' # This is real output from iwlist: s.replace(':',')').replace(' (','))').split(None,-1,')') ['Frequency', '2.462 GHz', 'Channel 11']

I wanted to preserve the '2.462 GHz' substr. Let's assume, that could come out as '900 MHz' or '11.3409 GHz'. The above code gets what I want in 1 shot, either way. Show me an easier way, that doesn't need multiple splits, and string re-assembly, ....and I'll use it.

Dave

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