Develop Reference

Call a python script from a python script within the same context

There is a python script start_test.py.
There is a second python script siple_test.py.
# pseudo code:
start_test.py --calls--> subprocess(python.exe simple_test.py, args_simple_test[])
The python interpreter for both scripts is the same. So instead of opening a new instance, I want to run simple_test.py directly from start_test.py. I need to preserve the sys.args environment. A nice to have would be to actually enter following code section in simple_test.py:
# file: simple_test.py
if __name__ == '__main__':
some_test_function()
Most important is, that the way should be a universal one, not depending on the content of the simple_test.py.
This setup would provide two benefits:
The call is much less resource intensive
The whole stack of simple_test.py can be debugged with pycharm
So, how do I execute the call of a python script, from a python script, without starting a new subprocess?

"Executing a script" is a somewhat blurry term.
Typically the if __name__== "__main__": part does the argument (sys.argv) decoding and then calls a worker function with explicit parameters. For clarity: It should not do anything else, since this additional work can't be called without creating a new process causing all the overhead you are trying to avoid.
You simply bypass that and call this implementing routine directly.
So you end up with start_test.py containing something like:
from simple_test import worker
# ...
worker(typed_arg1, typed_arg2)

How to run External collector from Scollector?

I am trying to run external sample.py script in /path-to-scollector/collectors/0 folder from scollector.
scollector.toml:
Host = "localhost:0"
ColDir="//path-to-scollector//collectors//"
BatchSize=500
DisableSelf=true
command to run scollector:
scollector-windows-amd64.exe -conf scollector.toml -p
But I am not getting the sample.py metrics in the output. It is expected to run continuosly and print output to cnosole. Also when I am running:
scollector-windows-amd64.exe -conf scollector.toml -l
my external collector is not listed.

In your scollector.toml, You should one line as below,
Filter=["sample.py "] .
in your sample.py, you need this line
#!/usr/bin/python

For running scollector on linux machine the above solution works well. But with windows its a bit tricky. Since scollector running on windows can only identify batch files. So we need to do a little extra work for windows.
create external collector :-
It can be written in any language python,java etc. It contains the main code to get the data and print to console.
Example my_external_collector.py
create a wrapper batch script :-
wrapper_external_collector.bat.
Trigger my_external_collector.py inside wrapper_external_collector.bat.
python path_to_external/my_external_collector.py
You can pass arguments to the script also.Only disadvantage is we need to maintain two scripts.

How to run python from C# without .exe file

I am a Python beginner and wrote some Python code that I want to run from my C# code.
In all the answers I have seen already, the way was to make a .exe file from the .py one and run it by system call.
However, I want it so that I do not need to make the .exe file and can write the commands with arguments as I could in the command line.
C:\Users\ntuser> python C:\Users\ntuser\Documents\run_python.py 3
Is there a way to do it?
I found a way to pass just one command—but I need to make two: 1. Go to "C:\Users\ntuser" 2. Run the Python code.
Thanks!

OK, so I found a solution.
Thanks to UnholySheep for the help.
What you need to do is:
Make the python as system variable
Go by code to your home directory:
Directory.SetCurrentDirectory(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile));
Add this code for calling the python code:
System.Diagnostics.Process process = new System.Diagnostics.Process();
System.Diagnostics.ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo();
startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;//if you want to hide the window
startInfo.FileName = "cmd.exe";
startInfo.Arguments = "/C python pytonPath\\python_code.py";
process.StartInfo = startInfo;
process.Start();
process.WaitForExit();//if you want to wait

How do you verify if an emailing script ran correctly?

I have written a bat script for robocopying. At the end of the script, it calls upon a python script that is used to send the contents of the log file to an email address. If the python script for one reason or another, didn't end up sending an email, I want to note that by appending a line to the log file. However, I can't seem to find a way within the bat file to check whether the python file ran as expected. This is all being done on windows 7 and the version of python is 2.7.5. Any insights or suggestions would be greatly appreciated.

Use a return code:
In the python script:
if email_was_not_sent:
sys.exit(1)
else:
sys.exit(0)
In the bat script:
# launch the Python script
if errorlevel 1 (
# Do your logging thing
)

Python Popen difficulties: File not found

I'm trying to use python to run a program.
from subprocess import Popen
sa_proc = Popen(['C:\\sa\\sa.exe','--?'])
Running this small snippit gives the error:
WindowsError: [Error 2] The system cannot find the file specified
The program exists and I have copy and pasted directly from explorer the absolute path to the exe. I have tried other things and have found that if I put the EXE in the source folder with the python script and use './sa.exe' then it works. The only thing I can think of is that I'm running the python script (and python) from a separate partition (F:).
Any ideas?
Thanks

As the docs say, "On Windows: the Popen class uses CreateProcess() to execute the child program, which operates on strings. If args is a sequence, it will be converted to a string using the list2cmdline() method.". Maybe that method is messing things up, so why not try the simpler approach of:
sa_proc = Popen('C:\\sa\\sa.exe --?')
If this still fails, then: what's os.environ['COMSPEC'] just before you try this? What happens if you add , shell=True to Popen's arguments?
Edit: turns out apparently to be a case of simple mis-spellling, as 'sa' was actually the program spelled SpamAssassin -- double s twice -- and what the OP was writing was spamassasin -- one double s but a single one the second time.

You may not have permission to execute C:\sa\sa.exe. Have you tried running the program manually?