因此，例如，您有：
a = [1,2]
b = [a,3]
c = b[:]
a[0] = 7
b[1] = 8
print c
你得到 [[7, 2], 3]
为什么不3变成8？
正如其他人所提到的，基本原理是分配时您正在执行“浅表复制” c。
要详细说明，您需要执行以下操作：
a = [1,2]
# a = list(1,2) at address AAA
b = [a, 3]
# b = list( [REFERENCE to AAA], 3) at address BBB
c = b[:]
# c = NEW list( b[0], b[1] ) at address CCC
# c = list( [REFERENCE to AAA], 3) at address CCC
a[0] = 7
# change item at AAA, offset [0], to 7
# 'b' points to AAA, so it will see change
# 'c' points to AAA, so it will see change
b[1] = 8
# change item at BBB, offset [1], to 8
# 'a' doesn't know about this, so it doesn't care.
# 'c' doesn't point to BBB, so it doesn't see the change.
print c
# Prints CCC offset [0], which refers to the AAA list, as changed,
# then prints CCC offset [1], which is still 3.
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