使用os.popen在python中创建列表 [英] Creating a list in python using os.popen

问题描述

以前，我已经能够使用类似于以下命令来创建列表:

Previously, I have been able to create lists using a command similar to the following:

os.popen('ls *.fits > samplelist')

现在，我正尝试通过按编号分组将文件整理到列表中.

Now I'm attempting to organize the files into lists by grouping them by number.

文件命名如下:

名称_0000_J.fits，名称_0001_J.fits，名称_0002_J.fits等

我试图运行此行代码，但它只是创建列表 skylist_J_1 并将其留空.

I've attempted to run this line of code but it just creates the list skylist_J_1 and leaves it empty.

os.popen('for num in {0000..0089} ; do ls Name_$num\_J.fits >> skylist_J_1 ; done')

我在命令行中运行了以上命令，它运行完美.任何见识将不胜感激.

I ran the above in a command line and it works perfectly. Any insight would be greatly appreciated.

我想出了这个解决方案，但它体积很大.希望有一种更清洁的方式来完成此任务.

I have come up with this solution but it is rather bulky. Hopefully there is a cleaner way to accomplish this.

def MkSkylist(qmin,qmax,name,band,quadrant):

    a = qmax-qmin+1

    ran = np.arange(qmin,qmax+1)
    num = [0]*a

    i = 0
    while i < a:
        num[i] = np.array2string(ran[i]).zfill(4)
        i = i + 1    

    os.popen('ls '+name+num[0]+'_'+band+'.fits > skylist_'+band+'_'+quadrant)

    i = 1
    while i < a:
        os.popen('ls '+name+num[0]+'_'+band+'.fits >> skylist_'+band+'_'+quadrant)
        i = i + 1

推荐答案

问题似乎与for循环的语法有关:即使该语法在bash中有效，但Python似乎并不喜欢它.甚至没有subprocess.Popen(..., shell=True).

The problem seems to be with the syntax of the for loop: even though that syntax is valid in bash, it seems Python doesn't like it. Not even with subprocess.Popen(..., shell=True).

因此，请尝试改用 seq :

os.popen("for num in $(seq 0 89); do printf "Name_%04dJ.fits\n" $num >> skylist_J_1; done");

将生成具有以下内容的文件skylist_J_1:

Which generates a file skylist_J_1 with this content:

Name_0001J.fits
Name_0002J.fits
Name_0003J.fits
Name_0004J.fits
...
Name_0086J.fits
Name_0087J.fits
Name_0088J.fits
Name_0089J.fits

还请注意，您可以将文件重定向放在外面，这与您的第一个示例更相似(使用>代替>>):

Also notice you can put the file redirection outside, which is more similar to your first example (using > instead of >>):

os.popen('for num in $(seq 0 89); do printf "Name_%04dJ.fits\n" $num; done > skylist_J_1')

这篇关于使用os.popen在python中创建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！