在Python中检索列表或字典中不存在的元素时，如何获取类似于false的值而不是error

my_list = [1, 2, 3, 4, 5]
element = 6

if element in my_list:
    print(f"{element} exists in the list.")
else:
    print(f"{element} does not exist in the list.")  # Output: 6 does not exist in the list.

my_list = [1, 2, 3, 4, 5]
element = 6

try:
    index = my_list.index(element)
except ValueError:
    index = None  # 或者你可以设置为False或其他你认为合适的值
    print(f"{element} does not exist in the list.")  # Output: 6 does not exist in the list.

my_dict = {'a': 1, 'b': 2, 'c': 3}
key = 'd'

if key in my_dict:
    print(f"{key} exists in the dictionary.")
else:
    print(f"{key} does not exist in the dictionary.")  # Output: d does not exist in the dictionary.

my_dict = {'a': 1, 'b': 2, 'c': 3}
key = 'd'

value = my_dict.get(key)
if value is not None:
    print(f"{key} exists in the dictionary with value {value}.")
else:
    print(f"{key} does not exist in the dictionary.")  # Output: d does not exist in the dictionary.