whitespace within a string

[Bart Nessux]

Is there a function/module that can be used to throw out extra whitespace
that appears within a string? The problem that I have is this: Before any
configuration is done to my files, they have lines with tabs in between the
words like this:

"disable = yes"

After configuring the files using the operating system's administration
tools, the OS rewrites the files to contain spaces instead of tabs. So now,
the file looks like this:

"disable = yes"

I would like my script to work in either situation. Right now, it only works
with spaces, not tabs. Below is the script:

def enable_ssh():
# works on 10.3 systems, not 10.2 systems
import os
os.chdir('/etc/xinetd.d')
find = 'disable = yes'
replace = 'disable = no'
x = file('ssh')
data = x.read()
x.close()
search = str.find(data, find)
if search >= 0:
data = data.replace(fi nd, replace)
outputFile = file('ssh', 'w')
outputFile.writ e(data)
outputFile.clos e()
print
print "SSH was disabled... service restarted!!!"
print
else:
print
print "SSH was enabled... no action taken."
print
enable_ssh()

[Jeff Epler]

Re: whitespace within a string

You can use the magic of no-arg split() to do this:
def canonize_whites pace(s):
return " ".join(s.split( ))
[color=blue][color=green][color=darkred]
>>> canonize_whites pace("a b\t\tc\td\t e")[/color][/color][/color]
'a b c d e'

A regular expression substituion can do the job too
def canonize_whites pace(s):
return re.sub('\s+', ' ', s)
[color=blue][color=green][color=darkred]
>>> canonize_whites pace("a b\t\tc\td\t e")[/color][/color][/color]
'a b c d e'

Of course, if 'x=y' is accepted just like 'x = y' and 'x = y', then
neither of these approaches is good enough.

def canonize_config _line(s):
if not '=' in s: return s
a, b = s.split("=", 1)
return "%s = %s" % (a.strip(), b.strip())[color=blue][color=green][color=darkred]
>>> [canonize_config _line(s) for s in[/color][/color][/color]
... ['x=y', 'x\t= y', ' x = y ', "#z"]]
['x = y', 'x = y', 'x = y', '#z']

Jeff

[Erik Max Francis]

Re: whitespace within a string

Bart Nessux wrote:
[color=blue]
> Is there a function/module that can be used to throw out extra
> whitespace
> that appears within a string? The problem that I have is this: Before
> any
> configuration is done to my files, they have lines with tabs in
> between the
> words like this:
>
> "disable = yes"[/color]

If you realy want to collapse any whitespace at all into a single space
character, how about:

' '.join(S.split( ))

--
__ Erik Max Francis && max@alcyone.com && http://www.alcyone.com/max/
/ \ San Jose, CA, USA && 37 20 N 121 53 W && &tSftDotIotE
\__/ One sword keeps the other in the sheath.
-- George Herbert

[Bart Nessux]

Re: whitespace within a string

Jeff Epler wrote:[color=blue]
> You can use the magic of no-arg split() to do this:
> def canonize_whites pace(s):
> return " ".join(s.split( ))
>[color=green][color=darkred]
> >>> canonize_whites pace("a b\t\tc\td\t e")[/color][/color]
> 'a b c d e'
>
> A regular expression substituion can do the job too
> def canonize_whites pace(s):
> return re.sub('\s+', ' ', s)
>[color=green][color=darkred]
> >>> canonize_whites pace("a b\t\tc\td\t e")[/color][/color]
> 'a b c d e'
>
> Of course, if 'x=y' is accepted just like 'x = y' and 'x = y', then
> neither of these approaches is good enough.
>
> def canonize_config _line(s):
> if not '=' in s: return s
> a, b = s.split("=", 1)
> return "%s = %s" % (a.strip(), b.strip())[color=green][color=darkred]
> >>> [canonize_config _line(s) for s in[/color][/color]
> ... ['x=y', 'x\t= y', ' x = y ', "#z"]]
> ['x = y', 'x = y', 'x = y', '#z']
>
> Jeff
>[/color]

Thanks for the tip. I'll give it a try.