Develop Reference

Save Scheduled Task (PYTHON Script NOT Batch file) Console Output to a file

I have found several solutions to save a batch file run from task scheduler to a txt file but the same technique of appending a > file.txt doesn't work for a python script which i am triggering through the task scheduler. Also tried >> file.txt
How to i save a python script console output to a txt file which is executed from the task scheduler?
This is the command that i am executing from the task scheduler, which is running fine except that it doest save the console output to the txt file.
Program Script - C:\Python27\python.exe
C:\Dropbox\Nightly_SSIM.py > C:\LAF\6.7\Nightly_Debug.txt

If you use the command line just like this in task scheduler:
C:\Dropbox\Nightly_SSIM.py > C:\LAF\6.7\Nightly_Debug.txt
then it just runs as a python process, where '>' re-direction is not recognized. I would try using the following in task scheduler:
cmd.exe /c C:\Dropbox\Nightly_SSIM.py > C:\LAF\6.7\Nightly_Debug.txt

.sh started by cron does not create file via python

I have this .sh which starts a python file. This python file generates a .txt when started via the commandline with sudo but doesn't when started via the .sh
Why doesn't the pyhton file give me a .txt when started with the cron and .sh?
When I use su -c "python /var/www/html/readdht.py > /var/www/html/dhtdata.txt" 2>&1 >/dev/null, .sh gives me output, but omits the newlines, so I get one big string.
The python file creates a .txt correctly when started from the commandline with sudo python readdht.py.
If the .sh the python file is started with su -c "python /var/www/html/readdht.py no .txt is created
What's going on?

Difficult to answer without more colour on your environment.
Here's how to solve this though: do not redirect your output to /dev/null. Then read in your cron log what happened. It seems very likely that your script fails, and therefore does not return anything to standard out, so does not create a file.
I highly suspect it is because you are using a python module, or python version or python path that is loaded in your bashrc. Crontab does not execute your bashrc, it's an independent environment, so you cannot assume that a script that runs correctly when you manually launch will work in your cron.
Try sourcing your bashrc in your cron task, and it's very likely to solve your problem.

Bash command not behaving as expected when invoked from Jenkins job

I have a python script which executes the following command:
commands.getstatusoutput("./some_program -bg; sleep 10; kill -SIGUSR2 `pidof
some_program`; kill -9 `pidof some_program`")
In short, this calls a program (some_program) and puts it in the background, then, after 10s, it sends a signal to the program to prompt it to dump some data into a csv file, after which we kill the program.
When I run the python script manually, it dumps the output to the csv file as expected. When I run the program through a Jenkins build however, the csv file is not created.
Any ideas?

Sounds like a permission problem to me, are you running jenkins with a different user? I would chmod 777 the folder temporally only to see if thatś the issue
– gerosalesc
It turns out it was an ownership issue. – user2548144

Python Script not running in cron

I am trying to run a Python script from cron. I am using crontab to run the command as a user instead of root. My Python script has the shebang at the top #! /usr/bin/env python and I did chmod +x it to make the script executable.
The script does work when running it from a shell but not when using crontab. I did check the /var/log/cron file and saw that the script runs but that absolutely nothing from stdout or stderr prints anywhere.
Finally, I made a small script that prints the date and a string and called that every minute that worked but this other script does not. I am not sure why I am getting these variable results...
Here is my entry in crontab
SHELL=/bin/bash
#min #hour day-of-month month day-of-week command
#-------------------------------------------------------------------------
*/5 * * * * /path/to/script/script.py
Here is the source code of my script that will not run from crontab but will run from the shell it is in when called like so ./script.py. The script is executable after I use the chmod +x command on it, by the way...:
#! /usr/bin/env python
#create a file and write to it
import time
def create_and_write():
with open("py-write-out.out", "a+") as w:
w.write("writing to file. hello from python. :D\n")
w.write("the time is: " + str(time.asctime()) + "\n")
w.write("--------------------------------\n")
def main():
create_and_write()
if __name__ == "__main__":
main()
EDIT
I figured out what was going wrong. I needed to put the absolute file paths in the script otherwise it would write to some directory I had not planned for.

Ok, I guess this thread is still going to help googlers.
I use a workaround to run python scripts with cron jobs. In fact, python scripts need to be handled with delicate care with cron job.
So I let a bash script take care of all of it.I create a bash script which has the command to run the python script. Then I schedule a cron job to run bash script. You can even use a redirector to log the output of bash command executing the python script.For example
#reboot /home/user/auto_delete.sh
auto_delete.sh may contain following lines:-
#!/bin/sh
echo $(date) >> bash_cron_log.txt
/usr/bin/python /home/user/auto_delete.py >> bash_cron_log.txt
So I don' need to worry about Cron Jobs crashing on python scripts.

You can resolve this yourself by following these steps:
Modify the cron as /path/to/script/script.py > /tmp/log 2> &1
Now, let the cron run
Now read the file /tmp/log
You will find out the reason of the issue you are facing, so that you can fix it.
In my experience, the issue is mostly with the environment.
In cron, the env variables are not set. So you may have to explicitly set the env for your script in cron.

I would like to emphasise one more thing. I was trying to run a python script in cron using the same trick (using shell script) and this time it didn't run. It was #reboot cron. So I used redirection in crontab as I mentioned in one of the above comments. And understood the problem.
I was using lot many file handlers in python script and cron runs the script from user's home directory. In that case python could not find the files used for file handlers and will crash.
What I used for troubleshooting was that I created a crontab as below. It would run the start.sh and throw all the stderror or stdoutput to file status.txt and I got error in status.txt saying that the file I used for file handler was not found. That was right because python script was executed by cron from user's home directory and then the script starts searching for files in home directory only.
#reboot /var/www/html/start.sh > /cronStatus/status.txt 2>&1
This will write everything happening during cron execution to status.txt file. You can see the error over there. I will again advice running python scripts using bash scripts for cronjobs. SOLUTION:- Either you use full path for all the files being used in script (which wasn't feasible for me, since I don't want script to be location dependent). Or you execute script from correct directory
So I created my cron as below-
#reboot cd /var/www/html/ && /var/www/html/start.sh
This cron will first change directory to correct location and then start the script. Now I don't have to worry about hardcoding full path for all files in script. Yeah, it may sound being lazy though ;)
And my start.sh looks like-
#!/bin/sh
/usr/bin/python /var/www/html/script.py
Hope it helps
Regards,
Kriss

I had a similar issue but with a little bit different scenario: I had a bash script (run.sh) and a Python script (hello.py). When I typed
sh run.sh
from the script directory, it worked; if I added the sh run.sh command in my crontab, it did not work.
To troubleshoot the issue I added the following line in my run.sh script:
printenv > env.txt
In this way you are able to see the environment variable used when you (or the crontab) run the script. By analyzing the differences between the env.txt generated from the manual run and the crontab run I noticed that the PWD variable was different. In my case I was able to resolve by adding the following line at the top of my .sh script:
cd /PYTHON_SCRIPT_ABSOLUTE_PATH/
Hope this could help you!

Another reason may be that the way we judged executed or not executed is wrong.

Problems running python script by windows task scheduler that does pscp

Not sure if anyone has run into this, but I'll take suggestions for troubleshooting and/or alternative methods.
I have a Windows 2008 server on which I am running several scheduled tasks. One of those tasks is a python script that uses pscp to log into a linux box, checks for new files and if there is anything new, copies them down to a local directory on the C: drive. I've put some logging into the script at key points as well and I'm using logging.basicConfig(level=DEBUG).
I built the command using a variable, command = 'pscp -pw xxxx name#ip:/ c:\local_dir' and then I use subprocess.call(command) to execute the command.
Now here's the weird part. If I run the script manually from the command line, it works fine. New files are downloaded and processed. However, if the Task Scheduler runs the script, no new files are downloaded. The script is running under the same user, but yet yields different results.
According to the log files created by the script and on the linux box, the script successfully logs into the linux box. However, no files are downloaded despite there being new files. Again, when I run it via the command line, files are downloaded.
Any ideas? suggestions, alternative methods?
Thanks.

You can use the windows Task Scheduler, but make sure the "optional" field "Start In" is filled in.
In the Task Scheduler app, add an action that specifies your python file to run "doSomeWork" and fill in the Start in (optional) input with the directory that contains the file.. So for example if you have a python file in:
C:\pythonProject\doSomeWork.py
You would enter:
Program/Script: doSomeWork.py
Start in (optional): C:\pythonProject

I had the same issue when trying to open an MS Access database on a Linux VM. Running the script at the Windows 7 command prompt worked but running it in Task Scheduler didn't. With Task Scheduler it would find the database and verify it existed but wouldn't return the tables within it.
The solution was to have Task Scheduler run cmd as the Program/Script with the arguments /c python C:\path\to\script.py (under Add arguments (optional)).
I can't tell you why this works but it solved my problem.

I'm having a similar issue. In testing I found that any type of call with subprocess stops the python script when run in task scheduler but works fine when run on the command line.
import subprocess
print('Start')
test = subprocess.check_output(["dir"], shell=True)
print('First call finished')
When run on command line this outputs:
Start
First call finished
When run from task scheduler the output is:
Start
In order to get the output from task scheduler I run the python script from a batch file as follows:
python test.py >> log.txt
I run the script through the batch file both on command line and through task scheduler.

Brad's answer is right. Subprocess needs the shell context to work and the task manager can launch python without that. Another way to do it is to make a batch file that is launched by the task scheduler that calls python c:\path\to\script.py etc. The only difference to this is that if you run into a script that has a call to os.getcwd() you will always get the root where the script is but you get something else when you make the call to cmd from task scheduler.

Last edit - start
After experiments... If you put there full path to python program it works without highest privileges (as admin). Meaning task settings like this:
program: "C:\Program Files\Python37\python.exe"
arguments: "D:\folder\folder\python script.py"
I have no idea why, but it works even if script uses subprocess and multiple threads.
Last edit - end
What I did is I changed task settings: checked Run with highest privileges. And task started to work perfectly while running python [script path].
But keep in mind, that title contains "Administrator: " at the begining... always...
P.S. Thanks guys for pointing out that subprocess is a problem. It made me think of task settings.
I had similar problem when one script is running from Windows Task Scheduler, and another one doesn't.
Running cmd with python [script path] didn't work for me on Windows 8.1 Embedded x64. Not sure why. Probably because of necessity to have spaces in path and issue with quotes.
Hope my answer helps someone. ;)

Create a batch file add your python script in your batch file and then schedule that batch file .it will work .
Example : suppose your python script is in folder c:\abhishek\script\merun.py
first you have to go to directory by cd command .so your batch file would be like :
cd c:\abhishek\script
python merun.py
it work for me .

Just leaving this for posterity: A similar issue I faced was resolved by using the UNC (\10.x.xx.xx\Folder\xxx)path everywhere in my .bat and .py scripts instead of the letter assigned to the drive (\K:\Folder\xxx).

I had this issue before. I was able to run the task manually in Windows Task Scheduler, but not automatically. I remembered that there was a change in the time made by another user, maybe this change made the task scheduler to error out. I am not sure. Therefore, I created another task with a different name, for the same script, and the script worked automatically. Try to create a test task running the same script. Hopefully that works!

For Anaconda installation of python in windows below solution worked for me
create a batch file with below
"C:\Users\username\Anaconda3\condabin\activate" && python "script.py" &&
deactivate
Setup task to run this batch file