Que Prime wrote:
>
> With the help of a tutor I was able to get the following code to work
> the way I want, but I'd like for it to parse through several files in
> one folder and create one output file.
>
> I'm thinking I need to add something like:
>
> def grab_files(files = []):
Default values are created when the function object is created, not on
each call.
So given this:
def test(a = []):
a.append(5)
print a
it works how you'd think it would for a passed list:
>>> x = []
>>> test(x)
[5]
>>> test(x)
[5, 5]
>>> x
[5, 5]
But when you don't pass it a value,
>>> test()
[5]
>>> test()
[5, 5]
>>> test()
[5, 5, 5]
As you can see, the default value isn't constant at [].
So if you do any operations on the default value, you should do
something like this instead:
def test(a=None):
if a == None:
a = []
which will give you the behavior you probably expected.
Other than that, I would suggest doing it like this:
files = ['a','b','c'] #construct this however you want
outfile = open('output','w')
for filename in files:
for line in open(filename):
#do your regular pattern matching stuff here.
outfile.close()
You can put this in a function but if this is all your code does then I
don't see the point of making a function,
it would just make the logic harder to follow.
I believe that the 'for line in open(filename):' will automatically read
in the file and then close the file stream,
but you may want to check that it does close the file.
Code untested.
-Luke
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