code: def rmlinematch(oldstr, infile, dryrun=False):
      
  
      linelist = []
      with open(infile) as reader:
          for item in reader:
              rmitem = re.match(r'.*{}'.format(oldstr), item)
              # if isinstance(rmitem) == isinstance(None):  Not quite sure the intent here
              if rmitem is None:
                  linelist.append(item)
      if dryrun is False:
          with open(infile, "w") as writer:
              writer.truncate()
              for line in linelist:
                  writer.writelines(line)
      elif dryrun is True:
          for line in linelist:
              print(line, end='')
      else:
          exit("""Unknown option specified to 'dryrun' argument,
                Usage: dryrun=<True|False>.""")
docs: Sed-like line deletion function based on given string..
      Usage: pysed.rmlinematch(<Unwanted string>, <Text File>)
      Example: pysed.rmlinematch('xyz', '/path/to/file.txt')
      Example:
      'DRYRUN': pysed.rmlinematch('xyz', '/path/to/file.txt', dryrun=True)
      This will dump the output to STDOUT instead of changing the input file.