I’m having trouble understanding exactly how this function works. At the top, there is the following comment:

// We want to call run_one_line, passing in the dictionary and the command string. We cannot do this through
// PyRun_SimpleString here because the command string may contain escaped characters, and putting it inside
// another string to pass to PyRun_SimpleString messes up the escaping. So we use the following more complicated
// method to pass the command string directly down to Python.

Two questions. First, can you elaborate on the issue with escaped characters? PyRun_SimpleString() should be able to accept strings with escaped characters in them. Are you saying this isn’t the case?

Second, can you explain the more complicated method that is being used? I see some pipes, a background thraeding doing some reading, something about dev/null, and a bunch of IOHandler stuff I don’t really understand.

If the entire function could be reduced to a single call to PyRun_SimpleString() if the escaping problem were fixed, then would it work to try to just manipulate the string directly to double-escape, or do soemthing else to it so that PyRun_SimpleString worked, to avoid this complicated logic?