How can I get a variable's value from a Python script in C++?

Question

so my problem is I have a Python script which reads datas from a sensor, at the end i want these datas to get into a string in the C++ code.

I have tried installing boost.python but didn't work. (The installation it self have failed, so im looking for a new option)

Basicly the question is:

I have a script like this:

def sum():
    string = "whateverdata"     // the data got read in
    return string

sum()

And i want to use it this way:


#include <string>

int main()
{
   string data = ???        // idk how 

  // processing the string  

   return 0;
}

Welcome to StackOverflow! I see you're a new contributor, so I advise you to check out [How to ask a good question](https://stackoverflow.com/help/how-to-ask) and [How to create a minimal reproducible example](https://stackoverflow.com/help/minimal-reproducible-example). Can you clarify what you mean by "the return value from a Python script"? Do you mean the state of some Python variables, the stdout from the script, or the return value of the script itself? Also, please elaborate on what you mean by "installing boost.python didn't work". — Brian61354270, Apr 04 '20 at 17:26
Sorry, I mean for the value of a python variable. The script reads the data in and put in string and i want the string to be given forward. — Nox, Apr 04 '20 at 17:30

score 0 · Accepted Answer · answered Apr 04 '20 at 20:32

I don't think you can do that. At least, I've never seen it personally.

I would see if you can do this either all in python, or all in c++.

If not, try bundling your python file into an exe using pyinstaller, and then making a system call to the python script from c++. It would look something like:

system("/path/to/pythonexe arg1 arg2");

To get the information into c++, you could have the python script continuously writing it to a text file, and the c++ program could read that same text file.

Alternatively, you could have the python script print the sensor data to the stdout and then read that into a buffer in c++. See this implementation for more details.

Let me know if you have any questions, good luck!

Yeah, the writing to file and read method is going to work for this problem, thanks. — Nox, Apr 05 '20 at 14:10

How can I get a variable's value from a Python script in C++?

1 Answers1