我想在函数中使用字典中的特定值- Python

def get_value_from_dict(dictionary, key):
    if key in dictionary:
        return dictionary[key]
    else:
        return None

# 示例字典
my_dict = {'name': 'John', 'age': 25, 'city': 'New York'}

# 调用函数获取特定值
name = get_value_from_dict(my_dict, 'name')
age = get_value_from_dict(my_dict, 'age')
city = get_value_from_dict(my_dict, 'city')

print(name)  # 输出：John
print(age)   # 输出：25
print(city)  # 输出：New York