input variable into python call subprocess

Question

I have a small python snippet that calls a larger program (I did not write the larger one).

call(['function1', file1,  file2,  'data.labels=abc, xyz'])

The above works.

input ='abc, xyz'

Now I want to input "abc, xyz" as a variable holding this value

call(['function1', file1,  file2,  'data.labels=input'])

but it does not work.

How can I pass a variable value into variable data.labels within call subprocess.

A more specific question might be, "how do I take the string `'abc, xyz'` and somehow get the string `'data.labels=abc, xyz'`"? The answer isn't really specific to `call` at all, just ordinary string manipulation. — Kevin, Sep 09 '14 at 20:16
@Kevin: It is specific to `subprocess.call()` on Windows where `CreateProcess()` is used to start the child process that accepts a single string as a command, see `subprocess.list2cmdline()`. In other words, you can't pass arbitrary unescaped values on Windows because `list2cmdline()` doesn't cover all possible cases. — jfs, Sep 09 '14 at 22:29

score 2 · Accepted Answer · edited Sep 09 '14 at 20:17

2

call(['function1', file1,  file2,  'data.labels=%s' % input])

edited Sep 09 '14 at 20:17

chepner

answered Sep 09 '14 at 20:15

Jonas K

[`'data.labels=' + input`](http://stackoverflow.com/a/25753183/4279) seems like a more natural code. – jfs Sep 09 '14 at 22:31

score 1 · Answer 2 · answered Sep 09 '14 at 20:37

1

Or

call(['function1', file1,  file2,  'data.labels=' + input)

If for some reason, input is not a string.

call(['function1', file1,  file2,  'data.labels=' + str(input) )

answered Sep 09 '14 at 20:37

Robert Jacobs

score 0 · Answer 3 · answered Sep 09 '14 at 20:18

0

Another way to do the same:

call(['function1', file1,  file2,  'data.labels={0}'.format(input)])

answered Sep 09 '14 at 20:18

Raydel Miranda

3 Answers3