requests 模块的 requests.session() 功能

之前使用 requests 模块的时候，是直接 requests.get() 或者 requests.post() 发送GET请求或POST请求；当然也是可以带上 cookies 和 headers 的，但这都是一次性请求，你这次带着cookies信息，后面的请求还得带。这时候 requests.session() 就派上用场了，它可以自动处理cookies，做状态保持。

使用示例：

# 先实例化一个对象
session = requests.session()

# 后面用法和直接使用requests一样了
response = session.get(url)  # get请求
response = session.post(url, json=json_data)  # post请求
result = response.json()

使用实例：

比如登录抖音创作者平台，需要扫码授权

headers = {
        'User-Agent': "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36",
        'Referer': "https://creator.douyin.com/"
}

session = requests.session()

url = "https://sso.******.com/get_qrcode/?next=https:%2F%2Fcreator.douyin.com%2Fcreator-micro%2Fhome&aid=2906&service=https:%2F%2Fcreator.douyin.com&is_vcd=1&fp=ktv0uumo_gD7FPCuy_MfX7_44zL_9T1C_6i8sUgr4bDT6&_signature=_02B4Z6wo00101sT4NFgAAIDDp.L0MRPTY47E.DDAANCBkR36EPHb.UKQQDGsenolKJ1B9ZIKsRmMN1Lo5p4y-Shnacp.3qjY67FSttxF.sflFlqrTtdz3pJ8M3DCtlzB35tqqXl7pwkqcVr24c"

# 发起请求之前，我们可以打印一下session上下文请求对象里面的cookies
cookie_dict = requests.utils.dict_from_cookiejar(session.cookies)
print("======cookie_dict:", cookie_dict)

response = session.get(url, headers=headers)
result = response.json()
qrcode = result['data']['qrcode']

打印的结果：

======cookie_dict: {}

获取到base64类型的二维码之后，转为图片

def showBase64():
    import base64
    from PIL import Image
    from io import BytesIO

    base64_str = "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"
    # 解码
    result = base64.b64decode(base64_str)
    print(result)
    print(type(result))

    # 将bytes结果转化为字节流
    bytes_stream = BytesIO(result)
    roiimg = Image.open(bytes_stream)
    # roiimg.show()
    imgByteArr = BytesIO()  # 初始化一个空字节流
    roiimg.save(imgByteArr, format('PNG'))  # 把我们得图片以‘PNG’保存到空字节流
    imgByteArr = imgByteArr.getvalue()  # 无视指针，获取全部内容，类型由io流变成bytes
    with open("abc.png", 'wb') as f:
        f.write(imgByteArr)

手机扫码确认授权登录之后，我们再看下cookies信息

=== cookie_dict: {
	'n_h': 'WGbUaxjyFD8F4IMOz-fEK6iA958s6jweL2yVh7I',
	'passort_auth_status': '9ef800e1355e39af884d7b3e172b%2C',
	'pasport_auth_status_ss': '9ef800e1355ede9af884d7b3e172b%2C',
	'passort_csrf_token': '3f51c55b800f337b8281b70b68f1',
	'pasport_csrf_token_default': '3f51c55b800f3327b8281b70b68f1',
	'sesionid': '3806868312dd537a32b407d24bbe',
	'sesionid_ss': '3806868312dd5379a32b407d24bbe',
	'sid_uard': '3806868312dd537482b407d24bbe%7C1632657359%7C5184000%7CThu%2C+25-Nov-2021+11%3A55%3A59+GMT',
	'sid_t': '3806868312dd537432b407d24bbe',
	'sid_cp_v1': '1.0.0-KDY3NzI3MjUwOGhkOTZhMGMxNGNiY2I1ZThhYTczNzhjYzAyODkKFQj43Y-WnQMQz7_BigYY2hY4BkD0BxoCaGwiIDM4MDY4NjgzMTJkZDUzNzQ4NTlhMzJiNDA3ZDI0YmJl',
	'ssid_cp_v1': '1.0.0-KDY3NzI3MGQwOThkOTZhMGMxNGNiY2I1ZThhYTczNzhjYzAyODkKFQj43Y-WnQMQz7_BigYY2hY4BkD0BxoCaGwiIDM4MDY4NjgzMTJkZDUzNzQ4NTlhMzJiNDA3ZDI0YmJl',
	'sso_ud_tt': '64ec6781371386b133f88c6768d3',
	'sso_ud_tt_ss': '64ec67813713859df33f88c6768d3',
	'toutio_sso_user': '142588d2f1ea42c3841130987671',
	'toutio_sso_user_ss': '142588d2f1fea42c3841130987671',
	'uid_t': '0738744985dd4750fa23c564b6e5e',
	'uid_t_ss': '0738744985dd4750fac3c564b6e5e'
}

可以看到，授权之后抖音的后台对这个请求设置了好多cookie(上图展示的cookie有删减)，我们可以把这些cookies保存到字典，或者数据库，可以在cookie未过期的时候，继续拿着这些cookie请求登录过的接口。当然了，把字典的cookie设置到请求里面 session = requests.session() 也是很方便的，如下:

# 实例化对象
session = requests.session()

# 给 requests.session() 对象设置cookie信息
session.cookies = requests.utils.cookiejar_from_dict(cookies_dict)

# 下面还是拿着 session 去请求
session.post(url) 或者 session.get(url) 等等

有cookie设置过期时间的，可以获取cookie过期时间

@classmethod
def get_cookie_expires(cls, jar_cookies):
    """
    获取 jar_cookies 里面 sessionid 或 sessionid_ss 或 sid_tt 的有效期
    """
    result = None
    for item in jar_cookies:
        if item.name == "sessionid" or item.name == "sessionid_ss" or item.name == "sid_tt":
            timestamp = item.expires
            if timestamp:
                result = cls.timestamp_to_datetime(timestamp)
    return result

@staticmethod
def timestamp_to_datetime(timestamp):
    """
    时间戳转datetime
    :param timestamp:
    :return: datetime
    """
    result = datetime.fromtimestamp(timestamp)
    return result

是不是感觉很好用，记录一下，如果能帮助到大家更好