Creating LF, NEL line terminators by accident? (python3)

[MRAB]

On 2019-03-26 19:55, Adam Funk wrote:
> Hi,
> 
> I have a Python 3 (using 3.6.7) program that reads a TSV file, does
> some churning with the data, and writes a TSV file out.
> 
> #v+
> print('reading', options.input_file)
> with open(options.input_file, 'r', encoding='utf-8-sig') as f:
>      for line in f.readlines():
>          row = line.split('\t')
>          # DO STUFF WITH THE CELLS IN THE ROW
> 
> # ...
> 
> print('writing', options.output_file)
> with open(options.output_file, 'w', encoding='utf-8') as f:
>      # MAKE THE HEADER list of str
>      f.write('\t'.join(header) + '\n')
> 
>      for doc_id in sorted(all_ids):
>      	# CREATE A ROW list of str FOR EACH DOCUMENT ID
> 	f.write('\t'.join(row) + '\n')
> #v-
> 
> I noticed that the file command on the output returns "UTF-8 Unicode
> text, with very long lines, with LF, NEL line terminators".
> 
> I'd never come across NEL terminators until now, and I've never
> (AFAIK) created a file with them before.  Any idea why this is
> happening?
> 
> (I tried changing the input encoding from 'utf-8-sig' to 'utf-8' but
> got the same results with the output.)
> 
Does the input contain any NEL? Do the strings that you write out 
contain them?