code: def work_in(dirname=None):
      
      curdir = os.getcwd()
      try:
          if dirname is not None:
              os.chdir(dirname)
  
          requests_cache.configure(expire_after=60 * 10 * 10)
          changes.initialise()
  
          yield
  
      finally:
          os.chdir(curdir)
docs: Context manager version of os.chdir. When exited, returns to the working
      directory prior to entering.