import types aaa = 0 print type(aaa) if type(aaa) is types.IntType: print "the type of aaa is int" if isinstance(aaa,int): print "the type of aaa is int" bbb = 'hello' print type(bbb) if type(bbb) is types.StringType: print "the type of bbb is string" if isinstance(bbb,str): print "the type of bbb is string" #if the type is NoneType,the isinstance does not work #we should judge the NoneType like below #if row is None #if type(row) is types.NoneType #In my opinion,use the types to judge the type of a param is convinient