os.path.join (folder, filename) ensures the path is correct for the system. On Windows, it uses backslashes (reports\summary.txt); on Linux and macOS it uses forward slashes (reports/summary.txt).
The FIND function allows you to find a text string within another. It returns the position at which a character or string begins within another text string. The output of the above function will be 5, ...
The Visual Studio solution can be used to build the C++ code and the generated C# bindings. It also generates the language wrappers for Java and Python, and builds the native interface DLLs too (in ...