Matlab相当于"endsWith":如何过滤有关扩展名的文件名列表? [英] Matlab equivalent of `endsWith`: How to filter list of filenames regarding their extension?

问题描述

是否存在与endswith函数等效的MATLAB，该函数可以在Python，Java等中使用?

Is there a MATLAB equivalent of the endswith function available in Python, Java etc.?

我想按字符串的结尾过滤字符串列表，例如列表:

I would like to filter a list of Strings by their endings, e.g. the list:

a.tif
b.jpg
c.doc
d.txt
e.tif

应使用endwith('.tif')进行过滤以得出:

should be filtered by endswith('.tif') to result in:

a.tif
e.tif

这是我要在Python中执行的操作:

Here's how I would do it in Python:

textList = ['a.tif','b.jpg','c.doc','d.txt','e.tif'];
filteredList = filter(lambda x:x.endswith('.tif'), textList)

这是我在MATLAB中尝试过的:

This is what I tried in MATLAB:

textList = {'a.tif'; 'b.jpg'; 'c.doc'; 'd.txt'; 'e.tif'};
found = strfind(textList, '.tif');
a = zeros(size(found)); for k = 1:size(found), a(k)=~isempty(found{k}); end;
textList(logical(a))

我可能不得不用regexp替换strfind来查找字符串末尾的出现.总的来说，我认为这是实现目标的一种相当复杂的方法. 有没有一种简便的方法可以在MATLAB中过滤列表?

I might have to replace strfind by regexp to find occurences at the end of the string. In general, I think this is a rather complicated way of achieving the goal. Is there an easier way to filter the list in MATLAB?

推荐答案

使用正则表达式可能非常有效:

Probably quite efficient is to use regular expressions:

filelist = {'a.tif'
            'c.doc'
            'd.txt'
            'e.tif'}

filtered = regexp( filelist ,'(\w*.txt$)|(\w*.doc$)','match')
filtered = [filtered{:}]

说明:

(\w*.txt$)将返回以.txt结尾的所有文件名\w*，而(\w*.doc$)将返回以.doc结尾的所有文件名\w*. |只是逻辑运算符.

(\w*.txt$) will return all filenames \w* which end $ with .txt and (\w*.doc$) will return all filenames \w* which end $ with .doc. The | is just the logical operator.

特别是如果您只想过滤一个文件扩展名，那真的很方便:

Especially if you just want to filter for one file extension, it is really handy:

fileExt = 'tif';
filtered = regexp( filelist ,['\w*.' fileExt '$'],'match')
filtered = [filtered{:}]

也可以过滤多个文件扩展名，但是您需要创建更长的 regex :

Filtering multiple file extensions is also possible, but you need to create a longer regex:

fileExt = {'doc','txt'};
dupe = @(x) repmat({x},1,numel(fileExt))
filter = [dupe('(\w*.'); fileExt(:).'; dupe('$)'); dupe('|')] %'

filtered = regexp( filelist, [filter{1:end-1}], 'match')
filtered = [filtered{:}]

这篇关于Matlab相当于"endsWith":如何过滤有关扩展名的文件名列表?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！