2

I am trying to generate a list from another list:

lista = [u'http://www.fetise.com/apparel/shirts',
 u'http://www.fetise.com/apparel/tees',
 u'http://www.fetise.com/apparel/tops-and-tees',
 u'http://www.fetise.com/accessories/belts',
 u'http://www.fetise.com/accessories/cufflinks',
 u'http://www.fetise.com/accessories/jewellery',
 u'http://www.fetise.com/accessories/lighters',
 u'http://www.fetise.com/accessories/others',
 u'http://www.fetise.com/accessories/sunglasses',
 u'http://www.fetise.com/accessories/ties-cufflinks',
 u'http://www.fetise.com/accessories/wallets',
 u'http://www.fetise.com/accessories/watches',
 u'http://www.fetise.com/footwear/boots',
 u'http://www.fetise.com/footwear/casual',
 u'http://www.fetise.com/footwear/flats',
 u'http://www.fetise.com/footwear/heels',
 u'http://www.fetise.com/footwear/loafers',
 u'http://www.fetise.com/footwear/sandals',
 u'http://www.fetise.com/footwear/shoes',
 u'http://www.fetise.com/footwear/slippers',
 u'http://www.fetise.com/footwear/sports',
 u'http://www.fetise.com/innerwear/boxers',
 u'http://www.fetise.com/innerwear/briefs',
 u'http://www.fetise.com/personal-care/deos',
 u'http://www.fetise.com/personal-care/haircare',
 u'http://www.fetise.com/personal-care/perfumes',
 u'http://www.fetise.com/personal-care/personal-care',
 u'http://www.fetise.com/personal-care/shavers',
 u'apparel/tees/gifts-for-her',
 u'footwear/sandals/gifts-for-her',
 u'footwear/shoes/gifts-for-her',
 u'footwear/heels/gifts-for-her',
 u'footwear/flats/gifts-for-her',
 u'footwear/ballerinas/gifts-for-her',
 u'footwear/loafers/gifts-for-her']

By using this: 

["http://www.fetise.com/" + i for i in lista if "http://www.fetise.com/" not in i]

Output is:

[u'http://www.fetise.com/apparel/tees/gifts-for-her',
 u'http://www.fetise.com/footwear/sandals/gifts-for-her',
 u'http://www.fetise.com/footwear/shoes/gifts-for-her',
 u'http://www.fetise.com/footwear/heels/gifts-for-her',
 u'http://www.fetise.com/footwear/flats/gifts-for-her',
 u'http://www.fetise.com/footwear/ballerinas/gifts-for-her',
 u'http://www.fetise.com/footwear/loafers/gifts-for-her']

But I need this output:

[u'http://www.fetise.com/apparel/shirts',
 u'http://www.fetise.com/apparel/tees',
 u'http://www.fetise.com/apparel/tops-and-tees',
 u'http://www.fetise.com/accessories/belts',
 u'http://www.fetise.com/accessories/cufflinks',
 u'http://www.fetise.com/accessories/jewellery',
 u'http://www.fetise.com/accessories/lighters',
 u'http://www.fetise.com/accessories/others',
 u'http://www.fetise.com/accessories/sunglasses',
 u'http://www.fetise.com/accessories/ties-cufflinks',
 u'http://www.fetise.com/accessories/wallets',
 u'http://www.fetise.com/accessories/watches',
 u'http://www.fetise.com/footwear/boots',
 u'http://www.fetise.com/footwear/casual',
 u'http://www.fetise.com/footwear/flats',
 u'http://www.fetise.com/footwear/heels',
 u'http://www.fetise.com/footwear/loafers',
 u'http://www.fetise.com/footwear/sandals',
 u'http://www.fetise.com/footwear/shoes',
 u'http://www.fetise.com/footwear/slippers',
 u'http://www.fetise.com/footwear/sports',
 u'http://www.fetise.com/innerwear/boxers',
 u'http://www.fetise.com/innerwear/briefs',
 u'http://www.fetise.com/personal-care/deos',
 u'http://www.fetise.com/personal-care/haircare',
 u'http://www.fetise.com/personal-care/perfumes',
 u'http://www.fetise.com/personal-care/personal-care',
 u'http://www.fetise.com/personal-care/shavers',
 u'http://www.fetise.com/apparel/tees/gifts-for-her',
 u'http://www.fetise.com/footwear/sandals/gifts-for-her',
 u'http://www.fetise.com/footwear/shoes/gifts-for-her',
 u'http://www.fetise.com/footwear/heels/gifts-for-her',
 u'http://www.fetise.com/footwear/flats/gifts-for-her',
 u'http://www.fetise.com/footwear/ballerinas/gifts-for-her',
 u'http://www.fetise.com/footwear/loafers/gifts-for-her']

Can someone please tell me how I can use if else with for loop in the condensed form...

4

2 回答 2

3

在列表推导的左侧使用条件表达式：

["http://www.fetise.com/" + i if "http://www.fetise.com/" not in i else i for i in lista]

这会产生：

>>> pprint(["http://www.fetise.com/" + i if "http://www.fetise.com/" not in i else i for i in lista])
[u'http://www.fetise.com/apparel/shirts',
 u'http://www.fetise.com/apparel/tees',
 u'http://www.fetise.com/apparel/tops-and-tees',
 u'http://www.fetise.com/accessories/belts',
 u'http://www.fetise.com/accessories/cufflinks',
 u'http://www.fetise.com/accessories/jewellery',
 u'http://www.fetise.com/accessories/lighters',
 u'http://www.fetise.com/accessories/others',
 u'http://www.fetise.com/accessories/sunglasses',
 u'http://www.fetise.com/accessories/ties-cufflinks',
 u'http://www.fetise.com/accessories/wallets',
 u'http://www.fetise.com/accessories/watches',
 u'http://www.fetise.com/footwear/boots',
 u'http://www.fetise.com/footwear/casual',
 u'http://www.fetise.com/footwear/flats',
 u'http://www.fetise.com/footwear/heels',
 u'http://www.fetise.com/footwear/loafers',
 u'http://www.fetise.com/footwear/sandals',
 u'http://www.fetise.com/footwear/shoes',
 u'http://www.fetise.com/footwear/slippers',
 u'http://www.fetise.com/footwear/sports',
 u'http://www.fetise.com/innerwear/boxers',
 u'http://www.fetise.com/innerwear/briefs',
 u'http://www.fetise.com/personal-care/deos',
 u'http://www.fetise.com/personal-care/haircare',
 u'http://www.fetise.com/personal-care/perfumes',
 u'http://www.fetise.com/personal-care/personal-care',
 u'http://www.fetise.com/personal-care/shavers',
 u'http://www.fetise.com/apparel/tees/gifts-for-her',
 u'http://www.fetise.com/footwear/sandals/gifts-for-her',
 u'http://www.fetise.com/footwear/shoes/gifts-for-her',
 u'http://www.fetise.com/footwear/heels/gifts-for-her',
 u'http://www.fetise.com/footwear/flats/gifts-for-her',
 u'http://www.fetise.com/footwear/ballerinas/gifts-for-her',
 u'http://www.fetise.com/footwear/loafers/gifts-for-her']
于 2013-06-21T10:44:49.773 回答
1

不要过滤，您只需要更改新列表的值：

["http://www.fetise.com/" + i if  "http://www.fetise.com/" not in i else i for i in lista]
于 2013-06-21T10:46:52.283 回答