code: def parseFile(self, filename):
          
          modname = self.filenameToModname(filename)
          module = Module(modname, filename)
          self.modules[modname] = module
          if self.trackUnusedNames:
              module.imported_names, module.unused_names = \
                  find_imports_and_track_names(filename,
                                               self.warn_about_duplicates,
                                               self.verbose)
          else:
              module.imported_names = find_imports(filename)
              module.unused_names = None
          dir = os.path.dirname(filename)
          module.imports = set(
              [self.findModuleOfName(imp.name, imp.level, filename, dir)
               for imp in module.imported_names])
docs: Parse a single file.