008_python列表的传值与传址

一、

今天发现一个奇怪的现象,代码如下:

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aList = ['xyz', 'zara', 'abc', 'xyz','xysdfji','xywooudd'] for x in aList:     if x.startswith('xy'):         aList.remove(x) print "List : ", aList   输出如下=>发现没有最后一个元素也是以xy开头,但是没有删除掉 List :  ['zara', 'abc', 'xysdfji']

二、换成如下的就可以了

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aList = ['xyz', 'zara', 'abc', 'xyz','xysdfji','xywooudd'] for x in aList[:]:     if x.startswith('xy'):         aList.remove(x) print "List : ", aList输出如下=>发现没有最后一个元素也是以xy开头,但是没有删除掉 List :  ['zara', 'abc']

三、比较它们两个的区别

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aList = ['xyz', 'zara', 'abc', 'xyz','xysdfji','xywooudd'] print id(aList) print id(aList[:]) print "------------" for y in aList:     print y print "----------" for x in aList[:]:     print

输出如下=>

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4534445984 4534446200 ------------ xyz zara abc xyz xysdfji xywooudd ---------- xyz zara abc xyz xysdfji xywooudd