PyShell.py 文件源码

def idle_showwarning(message, category, filename, lineno,
                         file=None, line=None):
        if file is None:
            file = warning_stream
        try:
            file.write(warnings.formatwarning(message, category, filename,
                                              lineno, line=line))
        except IOError:
            pass  ## file (probably __stderr__) is invalid, warning dropped.