inplace text filter - without writing file
Sayth Renshaw
flebber.crue at gmail.com
Sun Oct 2 01:33:05 EDT 2016
On Sunday, 2 October 2016 16:19:14 UTC+11, Sayth Renshaw wrote:
> On Sunday, 2 October 2016 12:14:43 UTC+11, MRAB wrote:
> > On 2016-10-02 01:21, Sayth Renshaw wrote:
> > > Hi
> > >
> > > I have a fileobject which was fine however now I want to delete a line from the file object before yielding.
> > >
> > > def return_files(file_list):
> > > for filename in sorted(file_list):
> >
> > When joining paths together, it's better to use 'os.path.join'.
> >
> > > with open(dir_path + filename) as fd:
> > > for fileItem in fd:
> > > yield fileItem
> > >
> > > Ned gave an answer over here http://stackoverflow.com/a/6985814/461887
> > >
> > > for i, line in enumerate(input_file):
> > > if i == 0 or not line.startswith('#'):
> > > output.write(line)
> > >
> > > which I would change because it is the first line and I want to rid <!--
> > >
> > > for i, line in enumerate(input_file):
> > > if line.startswith(<!--'):
> > > output.write(line)
> > >
> > > However I do not want to write the file I want to restore all the enumerated files back to the fileItem I need to yield.
> > >
> > > How do I do this?
> > >
> > You use the logic of the answer from StackOverflow in your
> > 'return_files' function:
> >
> > def return_files(file_list):
> > for filename in sorted(file_list):
> > with open(dir_path + filename) as fd:
> > for fileItem in fd:
> > if keep_item(fileItem):
> > yield fileItem
> >
> >
> > If you need to know the line number when deciding whether to keep a
> > line, use enumerate too:
> >
> > def return_files(file_list):
> > for filename in sorted(file_list):
> > with open(dir_path + filename) as fd:
> > for i, fileItem in enumerate(fd):
> > if keep_item(fileItem, i):
> > yield fileItem
>
> I just can't quite get it.
>
> def return_files(file_list):
> for filename in sorted(file_list):
> file = os.path.join(dir_path, filename)
> print(file)
> with open(file) as fd:
> print(fd)
> for fileItem in fd:
> print(fileItem)
> for line in fileItem:
> print(line[0])
> if line.startswith('<!--'):
> print(line[1:])
> yield line[1:]
> else:
> yield line[:]
>
> I maybe over baking it but just not getting it right.
>
> Sayth
Aargh, half solved it, now it works except I am creating a list as the yielded item and lxml doesn't accept list it wants the file.
def return_files(file_list):
"""
Take a list of files and return file when called.
Calling function to supply attributes
"""
for filename in sorted(file_list):
file = os.path.join(dir_path, filename)
with open(file, 'r') as fd:
data = fd.read().splitlines(True)
if data[0].startswith('<!--'):
print(data[1:])
yield data[1:]
else:
yield data[0:]
Cheers
Sayth
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