docs: def num_sequences(fileh):
    """
      Determine how many sequences there are in fasta file/stream.
  
      :param fileh: the stream to read the fasta data from, or a string giving
                    the filename of the file to load. Note that if a stream is
                    given, it will be consumed by this function
      :return: the number of sequences in this fasta stream/file
    """
    if type(fileh).__name__ == "str":
      fh = open(fileh)
    else:
      fh = fileh
    count = 0
    for _ in fastaIterator(fh):
      count += 1
    return count