code: def get_file_fullpath(name, dirname=None):
          # type: (AnyStr, Optional[AnyStr]) -> Optional[AnyStr]
          
          if name is None:
              return None
          if is_string(name):
              name = str(name)
          else:
              raise RuntimeError('The input function name or path must be string!')
          for sep in ['\\', '/', os.sep]:  # Loop all possible separators
              if sep in name:  # name is full path already
                  name = os.path.abspath(name)
                  return name
          if dirname is not None:
              dirname = os.path.abspath(dirname)
              name = dirname + os.sep + name
          return name
docs: Return full path if available.