2021-10-05 python：AttributeError: ‘NoneType‘ object has no attribute ‘append‘

Traceback (most recent call last):
  File "D:C worldpy实验03.py", line 36, in
    APPEND=APPEND.append(random.randint(1,100000))
AttributeError: 'NoneType' object has no attribute 'append'

 把    APPEND=APPEND.append(random.randint(1,100000))变成

APPEND=APPEND.append(random.randint(1,100000))
#错
    
APPEND.append(random.randint(1,100000))
#对

同样的

print(a.reverse)
#错
a=a.reverse
#错

a.reverse
print(a)
#对