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So I've been using this Pythonista Project Template to be able to use some SymPy in my iOS App. This is working fine with following code :

//Run the main script:
    if (scriptPath) {
        NSString *script = @"from sympy import *\ninit_printing(use_unicode=True)\nx = Symbol('x')\nprint(solve(x**2 - 1, x))";
        if (script) {
            [[PythonInterpreter sharedInterpreter] run:script asFile:scriptPath];
        } else {
            NSLog(@"Could not load main.py (make sure its encoding is UTF-8)");
        }
    } else {
        NSLog(@"Could not find main.py");
    }

So in this template there is a script called "captureoutput.py" wich looks like the following :

def _capture_output_main():
    import _outputcapture
    import sys

    class StdoutCatcher (object):
        def __init__(self):
            self.encoding = 'utf8'
        def write(self, s):
            if isinstance(s, str):
                _outputcapture.CaptureStdout(s)
            elif isinstance(s, unicode):
                _outputcapture.CaptureStdout(s.encode('utf8'))
        def writelines(self, lines):
            for line in lines:
                self.write(line + '\n')
        def flush(self):
            pass

    class StderrCatcher (object):
        def __init__(self):
            self.encoding = 'utf8'
        def write(self, s):
            if isinstance(s, str):
                _outputcapture.CaptureStderr(s)
            elif isinstance(s, unicode):
                _outputcapture.CaptureStderr(s.encode('utf8'))
        def flush(self):
            pass

    class StdinCatcher (object):
        def __init__(self):
            self.encoding = 'utf8'
        def read(self, len=-1):
            return _outputcapture.ReadStdin(len)

        def readline(self):
            return _outputcapture.ReadStdin()

    sys.stdout = StdoutCatcher()
    sys.stderr = StderrCatcher()
    sys.stdin = StdinCatcher()

_capture_output_main()
del _capture_output_main

This outputs into a OMTextView in the App but I want to have the output accessible without UI use. Like in an NSString or somethingIi can work with without using UI.

I hope I was able to clarify my problem ! Thanks for your help in advance !

All my best,
Robert

sys.stdout, and sys.stderr can be any object that looks like a file descriptor. So this fould actually be a file, which might be easiest since you could read it in ObjC, or it could be an StringIO

oldstdout = sys.stdout
sys.stdout = io.StringIO()

then you could get the value using getvalue(). To access that from the ObjC side, you might need to use some python c api functions.