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).

My hosting provider somehow messed up their python config and broke my website. I have SSH access but not root access. I'm looking for ideas on what might be going wrong. The problem, in a nutshell, ...

Package your Python applications for redistribution with one click, no compiling, and almost no additional software.