On 10/22/07, wang frank <[EMAIL PROTECTED]> wrote
>
>
> I have a big log file generated from matlabe, for each variable, it print
> the name of the variable and an empty line and then the value. such as:
>
> x1 =
>
> 0.1
>
> y =
>
> 7
>
> z =
>
> 6.7
>
> x1 =
>
> 0.5
>
> I want to use python to parse the file and selectively print out the
> vairable and its value. For example, I want to print out all the value
> related with x1, so the output will be
>
> x1 = 0.1
> x1 = 0.5.
>
>
Here is a fairly naive version with re named groups that should handle the
example you pasted.
In [62]: import re
In [63]: px = re.compile('(?P<variable>\w+)\s=\s+(?P<value>\d.*\d*)')
In [64]: for var in px.finditer(s):
print "%s = %s" %(var.group('variable'), var.group('value'))
....:
....:
a = 0.1
y = 7
z = 6.7
x1 = 0.5
To filter for only the x1's just test for the group named 'variable':
In [66]: for var in px.finditer(s):
....: if var.group('variable')=='x1':
....: print "%s = %s" %(var.group('variable'), var.group
('value'))
....:
....:
x1 = 0.5
But I'm betting these files get more complex than just the snippet you
included, in which case it's probably worth looking at pyparsing
http://pyparsing.wikispaces.com/ and regular expressions.
--
Travis Brady
http://travisbrady.com/
--
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