函数6：append/extend/

合并列表

# 方法一：append()
A = [91, 95, 97, 99]
B = [92, 93, 96, 98]
for i in A:
    B.append(i)
print(B)
[92, 93, 96, 98, 91, 95, 97, 99]

# 方法二：extend()
A = [91, 95, 97, 99]
B = [92, 93, 96, 98]
A.extend(B)
print(A)
[91, 95, 97, 99, 92, 93, 96, 98]

# 方法三：‘+‘ 
# '+'与extend()区别为'+'生成新列表，extend()在原列表上合并
A = [91, 95, 97, 99]
B = [92, 93, 96, 98]
C = A+B
print(C)
[91, 95, 97, 99, 92, 93, 96, 98]