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:

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

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

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=>

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