a = [1,2,3] 和 b = [,, ] 以及 b = [,, ] 的区别？

补充：

a=[1,2,3,4,5]，b=a和b=a[:]，有区别么？a = [1,2,3,4,5]b = ab1 = a[:]print(b)    #  [1, 2, 3, 4, 5]# print(b)   #  [1, 2, 3, 4, 5]b.append(6)print("a",a)  # a [1, 2, 3, 4, 5, 6]print("b",b)  # b [1, 2, 3, 4, 5, 6]  传递引用print("b1",b1) # b1 [1, 2, 3, 4, 5]   拷贝

# 一个列表A=[2，3，4]，Python如何将其转换成B=[(2,3),(3,4),(4,2)]？# B = zip(A, A[1:]+A[:1])# B = [(j,A[i+1]) if i < len(A) - 1 else (j,A[0]) for i, j in enumerate(A)]