How to append URLs to an array in python?

Question

How can I append URLs to a array in python, I was trying using the following code,

zone = ["z1", "z2", "z3"]
result_1 = []

for i in zone:
    result_val = os.system("gcloud command1 " +i+ " --command2")
    result_1.append(result_val)
print(result_1)

But when run this, my results are printing like below,

https://sample-domain.com/test/abc/1
https://sample-domain.com/test/abc/2
https://sample-domain.com/test/abc/3

But when I print the "result_1" it shows me below result

[0, 0, 0]

But I need the result like this,

["https://sample-domain.com/test/abc/1","https://sample-domain.com/test/abc/2","https://sample-domain.com/test/abc/3"]

How can I correct this issue ?

Any help would be greatly appreciated.

Thanks.

What's the exact command you're running there? The result is the exit error (0) that you add to the list. — baduker, Jul 01 '22 at 08:14
There is nothing wrong with the code to append to append to your list (we don't call it an array). The problem is that `result_val` is not the string that is printed by the command you are running - the output has **nothing to do with** the `os.system` function, just like how `print` and `return` have nothing to do with each other. Please see https://stackoverflow.com/questions/4760215 (I am out of duplicate close votes for today). — Karl Knechtel, Jul 01 '22 at 08:16

Pitto · Answer 1 · 2022-07-01T08:26:43.647

You need to store in your list the standard output.
What you are doing now is only storing the return code.

It is possible to obtain a similar result using Popen from subprocess.

import subprocess

zone = ["z1", "z2", "z3"]
result_1 = []

for i in zone:
    proc = subprocess.Popen(["gcloud", "command1", i , "--command2"], stdout=subprocess.PIPE)
    for line in iter(proc.stdout.readline, ''):
        result_1.append(line.rstrip())
print(result_1)

score -1 · Answer 2 · edited Jul 01 '22 at 08:43

-1

You may want to use .check_output from subprocess module, as the comments suggest, you need to get the output printed in the console, not the result of os.system(), which returns a different value:

import subprocess

zone = ["z1", "z2", "z3"]
result_1 = []

for i in zone:
    res = subprocess.check_output(["gcloud", "command1", i, "--command2"])
    result_1.append(res)
print(result_1)

edited Jul 01 '22 at 08:43

tripleee

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answered Jul 01 '22 at 08:20

Cardstdani

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Not sure, but the `.stdout` in `res.stdout` seems odd: Doesn't `subprocess.check_output()` return bytes? – Timus Jul 01 '22 at 08:36
@Timus Indeed; updated the answer – tripleee Jul 01 '22 at 08:45
@tripleee Thanks for the edit, I wasn't sure about `.stdout` function usage in this case – Cardstdani Jul 01 '22 at 09:20

How to append URLs to an array in python?

2 Answers2