如何在Python中更新字典中键的值？

my_dict = {'key1': 'value1', 'key2': 'value2'}
my_dict['key1'] = 'new_value1'  # 更新'key1'的值
print(my_dict)  # 输出：{'key1': 'new_value1', 'key2': 'value2'}

my_dict = {'key1': 'value1', 'key2': 'value2'}
my_dict.update({'key1': 'new_value1'})  # 更新'key1'的值
print(my_dict)  # 输出：{'key1': 'new_value1', 'key2': 'value2'}

my_dict = {'key1': 'value1', 'key2': 'value2'}
my_dict = {key: 'new_value1' if key == 'key1' else value for key, value in my_dict.items()}
print(my_dict)  # 输出：{'key1': 'new_value1', 'key2': 'value2'}