请大家帮忙看看，为什么运用了副本，原来的列表也空了

def transform_messages(messasges,sent_messages):

‘’’发送全部信息’’’

while messages:

sending_message=messages.pop()

print(f’sending message:{sending_message}’)

sent_messages.append(sending_message)

def send_messages(messages,sent_messages):

‘’’打印未发送信息和已发送信息两个列表’’’

print(‘Here are the original messages’)

for message in messages:

print(message)

print(‘Here are the sent messages’)

for sent_message in sent_messages:

print(sent_message)

messages=[‘A’,’B’,”C”,”D”,”E”,”F”]

sent_messages=[]

transform_messages(messages[:],sent_messages)

send_messages(messages,sent_messages)

sending message:F
sending message:E
sending message:D
sending message:C
sending message:B
sending message:A
Here are the original messages
Here are the sent messages
F
E
D
C
B
A