Run WinSCP script in Python with parameters

I'm trying to run a WinSCP script that has a parameter %1%. I run the script in cmd as follows an d it runs fine:

"C:\Program Files (x86)\WinSCP\WinSCP.com" /script=<filepath> /log=<logpath> /parameter <param1>

But if I can't figure out how to pass the param1 value if I run it as a subprocess in Python. What am I doing wrong? I tried:

cmdFile = <filepath>
logfile = <logpath>
param = <param1>
subprocess.run(["C:\Program Files (x86)\WinSCP\WinSCP.com", "/script=" + cmdFile, "/log=" + logfile, param]  , shell=True)
subprocess.run(["C:\Program Files (x86)\WinSCP\WinSCP.com", "/script=" + cmdFile, "/log=" + logfile, "/parameter " + param]  , shell=True)
subprocess.run(["C:\Program Files (x86)\WinSCP\WinSCP.com", "/script=" + cmdFile, "/log=" + logfile, "/parameter //" + param]  , shell=True)```

Solution

Here is a self-contained example that solves your issue and can easily be tested by running some small local ftp host like ftpdmin (https://www.sentex.ca/~mwandel/ftpdmin/, no affiliation):

import subprocess

# create a test file
test_fn = 'test.txt'
with open(test_fn, 'w') as f:
    f.write(
        'Hello\n'
        'World\n'
    )

# create a script for WinSCP
script_fn = 'commands.txt'
with open(script_fn, 'w') as f:
    f.write(
        'open ftp://anonymous:@localhost\n'
        'put "%1%"\n'
        'put "%2%"\n'
        'exit'
    )

log_fn = 'log.txt'
# parameters to pass to the script (uploading the test file and the script)
parameters = [test_fn, script_fn]
# the adjusted command, passing '/parameter' and then just the parameters
subprocess.run([
    'C:\Program Files (x86)\WinSCP\WinSCP.com',
    '/script=' + script_fn,
    '/log=' + log_fn,
    '/parameter'
] + parameters, shell=True)

Note that I changed the variable names to be a bit more Pythonic, they weren't wrong, but there's always room for improvement :).

The issue with your own solutions was that you need to pass parameters to your script after a single /parameter parameter on the command line. For example:

winscp.com /script=commands.txt /parameter one two three

This would start the script in commands.txt and pass one, two and three to the script, where they would be accessible as %1% etc. (note that WinSCP recommends you surround them with quotes in the script if they can contain spaces)

In your attempts, you pass 1.) just the parameter, 2.) '/parameter param' as a single string, instead of two as expected by .run() and 3.) '/parameter //param' which has the same problem, but adds a superfluous double slash.

In the form that you wrote it, this would have been correct:

subprocess.run(["C:\Program Files (x86)\WinSCP\WinSCP.com", "/script=" + cmdFile, "/log=" + logfile, "/parameter", param], shell=True)