Using python 3 subprocess module's function throws error

Question

code:-

import subprocess
print(subprocess.run(['date']))

when run it:-

Traceback (most recent call last):

File "D:\PyProjects\selenium\0experiment.py", line 8, in <module>
print(subprocess.run(['date']))

File "D:\Users\anaconda3\lib\subprocess.py", line 488, in run
with Popen(*popenargs, **kwargs) as process:

File "D:\Users\anaconda3\lib\site-packages\spyder_kernels\customize\spydercustomize.py", line 104, in __init__
super(SubprocessPopen, self).__init__(*args, **kwargs)

File "D:\Users\anaconda3\lib\subprocess.py", line 800, in __init__
restore_signals, start_new_session)

File "D:\Users\anaconda3\lib\subprocess.py", line 1207, in _execute_child
startupinfo)

FileNotFoundError: [WinError 2] The system cannot find the file specified

I am completely new to these and was learning these stuffs from online videos...in which tutor's same code ran flawlessly. Here is the video (at 1:40)

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I also tried this code:

import subprocess
print(subprocess.run(['date'], shell=True))

But when ran, above code caused the console to run for long period of time and I have to terminate it manually (without printing anything on console). (WHY??)

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I googled a lot and read a few somewhat similar type of question having such kind of Error...but not able to help myself: for example this thread.

• What is this [WinError 2] , what causes this error?

• FileNotFoundError , what file is this program referring to?

• Is there any OS/system related prerequisites that needs to be fulfilled before programs using subprocess module can be executed?

• I'm using windows 10, Spyder IDE(not installed in C drive but in D drive) having latest version of python.

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Please explain in laymen terms. Thanks.

Answer 1

Try running date on a CMD terminal and it prompts you to enter a new date, That is what's causing your subprocess to hang up indefinitely. You're correct about using shell=True for this command. Use of shell expands your environment variables and the available list of file globs(this is what the win32 error means). Since date here is a specific windows command you need the shell. Using shell=True is also platform dependent so you might want to check what commands you're trying to execute.

Answer 2

I Have used this in SPyder as well and it runs correctly, my only concern (since I am also new on this) is why does the console asks you to enter a new date. but it works anyway...

import subprocess
subprocess.run(["date"], shell=True)

Output (in spanish):

La fecha actual es: jue. 27/07/2023 
Escriba la nueva fecha: (dd-mm-aa)

First line tells you the date, second line asks you to enter new date as explained above.