def seq_concat_seq(a, b):
 prefer = type(max([a, b], key=len))
 if (not isinstance(a, prefer)):
  a = prefer(a)
 if (not isinstance(b, prefer)):
  b = prefer(b)
 return (a + b)

def seq_concat_seq ( a , b ) : prefer = type ( max ( [ a , b ] , key = len ) ) if ( not isinstance ( a , prefer ) ) : a = prefer ( a ) if ( not isinstance ( b , prefer ) ) : b = prefer ( b ) return ( a + b )
concatenate two sequences: a + b .