Am 05.11.2012 11:54, schrieb andrea crotti:
Quite often I find convenient to get a filename or a file object as
argument of a function, and do something as below:
def grep_file(regexp, filepath_obj):
"""Check if the given text is found in any of the file lines, take
a path to a file or an opened file object
"""
if isinstance(filepath_obj, basestring):
fobj = open(filepath_obj)
else:
fobj = filepath_obj
for line in fobj:
if re.search(regexp, line):
return True
return False
This makes it also more convenient to unit-test, since I can just pass
a StringIO.
I do the same for the same reason, but I either pass in a file object or
the actual data contained in the file, but not a path.
But then there are other problems, for example if I pass a file
> object is the caller that has to make sure to close the file
handle..
I don't consider that a problem. If you open a file, you should do that
in a with expression:
with open(..) as f:
found = grep_file(regex, f)
That is also the biggest criticism I have with your code, because you
don't close the file after use. Another things is the readability of
your code:
grep_file("foo", "bar")
The biggest problem there is that I don't know which of the two
arguments is which. I personally would expect the file to come first,
although the POSIX grep has it opposite on the commandline. Consider as
alternative:
grep("foo", path="bar")
with open(..) as f:
grep("foo", file=f)
with open(..) as f:
grep("foo", data=f.read())
Using **kwargs, you could switch inside the function depending on the
mode that was used, extract lines accordingly and match these against
the regex.
Greetings!
Uli
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