python 将 help 输出的帮助信息写到文件

import sys
import pydoc

def output_help_to_file(filepath, request):
    f = open(filepath, 'w')
    sys.stdout = f
    pydoc.help(request)
    f.close()
    sys.stdout = sys.__stdout__
    return

import sys
output_help_to_file('abc.log', sys)

来源：https://stackoverflow.com/questions/11265603/how-do-i-export-the-output-of-pythons-built-in-help-function