code: def fromtsv(source=None, encoding=None, errors='strict', header=None, 
              **csvargs):
      
  
      csvargs.setdefault('dialect', 'excel-tab')
      return fromcsv(source, encoding=encoding, errors=errors, **csvargs)
docs: Convenience function, as :func:`petl.io.csv.fromcsv` but with different
      default dialect (tab delimited).