code: def open_txt(p):
      'Create sheet from `.txt` file at Path `p`, checking whether it is TSV.'
      with p.open_text() as fp:
          if options.delimiter in next(fp):    # peek at the first line
              return open_tsv(p)  # TSV often have .txt extension
          return TextSheet(p.name, pf open_txt(p):
      'Create sheet from `.txt` file at Path `p`, checking whether it is TSV.'
      with p.open_text() as fp:
          if options.delimiter in next(fp):    # peek at the first line
              return open_tsv(p)  # TSV often have .txt extension
          return TextSheet(p.name, p)
docs: Create sheet from `.txt` file at Path `p`, checking whether it is TSV.