Arc*_*rus 8 python list-comprehension list
最近我遇到了这个问题:
假设有一个我想要处理的内容列表:
process_list=["/test/fruit/apple","/test/fruit/pineapple","/test/fruit/banana","/test/tech/apple-pen","/test/animal/python","/test/animal/penguin"]
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我想用其他列表排除某些内容,例如:
exclude_list=["apple","python"]
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在我对其应用exclude_list之后,process_list应该是这样的(任何包含子的process_list项:
["/test/fruit/banana","/test/animal/penguin","/test/fruit/pineapple"]
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或者如果exclude_list是:
exclude_list=["pen","banana"]
应用过滤器后,process_list应为此:
["/test/fruit/apple","/test/fruit/pineapple","/test/animal/python"]
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所以我最初尝试的是:
for item in exclude_list:
for name in (process_list):
if item in name:
process_list.remove(name)
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当然这不起作用,因为for不允许在使用循环迭代它时从列表中删除元素.代码只删除了第一个匹配,然后停止了.
那么我想出了另一个列表的方法:
deletion_list=[] #Track names that need to be deleted
for item in exclude_list:
for name in (process_list):
if item in name:
deletion_list.append(name)
# A list comprehension
process_list=[ x for x in process_list if x not in deletion_list ]
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它有效,但我的胆量告诉我可能有更优雅的方式.现在需要另一个列表来存储需要删除的名称.有任何想法吗?
Moi*_*dri 14
您可以使用过滤器列表推导表达式all():
# Here: `p` is the entry from `process_list`
# `e` is the entry from `exclude_list`
>>> [p for p in process_list if all(e not in p for e in exclude_list)]
['/test/fruit/banana', '/test/animal/penguin']
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关于你的陈述:
当然这不起作用,因为不允许在使用for循环迭代它时从列表中删除元素.代码只删除了第一个匹配,然后停止了.
您可以迭代列表副本:
for item in list(exclude_list): # OR, for item in exclude_list[:]:
# ^-- Creates new copy ----------------------------^
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