python中如何判断值在不在字典中

for iterating_var in sequence:

   statements(s)

dict1={'name':'Lara','age':18}

#判断键在不在字典中

for one in dict1:

   if 'name' in dict1:#或dict1.keys()

       print('key在字典中！')

       break

#判断值在不在字典中

for one in dict1:

   if 'Lara' in dict1.values():

       print('value在字典中！')

       break