py辞書削除操作のテクニック

               list ,     list,    
dic = {'k1': 'alex', 'k2': 'wusir', 's1': '   '}
dic_del_list = []
#   key   'k'   
for k in dic:
if 'k' in k:
 dic_del_list.append(k)
for el in dic_del_list:
del dic[el]
print(dic)