ua.py

#coding:utf-8
import codecs
import json
import random
from config import HEADER


class RandomHeader:
    def __init__(self):
        self.ua = UserAgent()
        self.header = HEADER

    def Header(self, referer=''):
        header = self.header
        header['User-Agent'] = self.ua.random
        if referer:
            header['Referer'] = referer
        return header


class UserAgent(object):
    def __init__(self):
        self.data = self.load('ua.json')
        self.SHORTCUTS = {
            'ie': 'internetexplorer',
        }

    def load(self, db):
        with codecs.open(db, encoding='utf-8', mode='rb',) as fp:
            return json.load(fp)
        
    def __getitem__(self, attr):
        return self.__getattr__(attr)

    def __getattr__(self, attr):
        attr = attr.lower()

        if attr == 'random':
            attr = self.data['randomize'][
                str(random.randint(0, len(self.data['randomize']) - 1))
            ]
        else:
            if attr in self.SHORTCUTS:
                attr = self.SHORTCUTS[attr]

        try:
            return self.data['browsers'][attr][
                random.randint(
                    0, len(self.data['browsers'][attr]) - 1
                )
            ]
        except KeyError:
            return None

if __name__ == '__main__':
    ua = UserAgent()
    print ua['opera']
    print ua['ie']
    print ua.chrome
    print ua.firefox
    print ua.random