#!/usr/bin/python
# Filename: reference.py
print 'Simple Assignment'
shoplist = ['apple', 'mango', 'carrot', 'banana']
mylist = shoplist # mylist is just another name pointing to the same object!
del shoplist[0]
print 'shoplist is', shoplist
print 'mylist is', mylist
# notice that both shoplist and mylist both print the same list without
# the 'apple' confirming that they point to the same object
print 'Copy by making a full slice'
mylist = shoplist[:] # make a copy by doing a full slice
del mylist[0] # remove first item
print 'shoplist is', shoplist
print 'mylist is', mylist
# notice that now the two lists are different
（源文件：code/reference.py）
輸出
$ python reference.py
Simple Assignment
shoplist is ['mango', 'carrot', 'banana']
mylist is ['mango', 'carrot', 'banana']
Copy by making a full slice
shoplist is ['mango', 'carrot', 'banana']
mylist is ['carrot', 'banana']
它如何工作
大多數(shù)解釋已經(jīng)在程序的注釋中了。你需要記住的只是如果你想要復(fù)制一個列表或者類似的序列或者其他復(fù)雜的對象（不是如整數(shù)那樣的簡單 對象 ），那么你必須使用切片操作符來取得拷貝。如果你只是想要使用另一個變量名，兩個名稱都 參考 同一個對象，那么如果你不小心的話，可能會引來各種麻煩。
給 Perl 程序員的注釋
記住列表的賦值語句不創(chuàng)建拷貝。你得使用切片操作符來建立序列的拷貝。
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