如何从字典值中获取关键字

my_dict = {'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}
keyword = 'key2'
value = my_dict.get(keyword)
print(value)  # 输出：value2

my_dict = {'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}
keyword = 'key2'
value = my_dict[keyword]
print(value)  # 输出：value2

my_dict = {'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}
keyword = 'key2'
for key, value in my_dict.items():
    if key == keyword:
        print(value)  # 输出：value2
        break