'get method
:param url: target url
:param header: headers
:param retry_time: retry time when network error
:param timeout: network timeout
:param retry_flag: if retry_flag in content. do retry
:param retry_interval: retry interval(second)
:param args:
:param kwargs:
:return:'

def get(self, url, header=None, retry_time=5, timeout=30, retry_flag=list(), retry_interval=5, *args, **kwargs):

    headers = self.header
    if (header and isinstance(header, dict)):
        headers.update(header)
    while True:
        try:
            html = requests.get(url, headers=headers, timeout=timeout)
            if filter((lambda key: (key in html.content)), retry_flag):
                raise Exception
            else:
                return html
        except Exception as e:
            print e
            retry_time -= 1
            if (retry_time <= 0):
                return
            time.sleep(retry_interval)
