1 写文件如果是bytes类型的话，打开文件 open参数设置为wb
2 python2 默认包import是相对路径，python3是绝对路径
3 python3的dict没有has_key方法，用in
4 map() in Python 3 is a generator function, which is not serializeable in JSON. You can make it serializeable by converting it to a list
map()
5