python 语法错误

Question

如图 函数切片

def show_message(list[:],completed):
while list:
current=list.pop()
print(current)
completed.append(current)
messages=['1',
'2',
'3',
'4',
'5',
'6']
completed=[]
show_message(messages,completed)
print(completed)
print(messages)

D:\Anaconda3\envs\project2\python.exe E:/pythonProject/project2/main.py

File "E:\pythonProject\project2\main.py", line 1
def show_message(list[:],completed):
^
SyntaxError: invalid syntax

如果把[:]删了是没问题的 可是用切片为什么不行呢

Answer 1

函数参数要符合变量的命名规则，不能带[，:，]这些字符，要不语法错了。
要切片是在调用函数时做调用操作

def show_message(list,completed):
    while list:
        current=list.pop()
        print(current)
        completed.append(current)

messages=['1',
'2',
'3',
'4',
'5',
'6']
completed=[]
show_message(messages[:],completed)###########
print(completed)
print(messages)