After check the code, I found the header of api/v4 has not contains "X-Total-Pages", so we cannot get the total page. The "X-Next-Page" is a good solution, if the records are read to end, this attribute will empty.

params = {'page': 1}
resp = request(url, params)
for row in resp.json():
yield row
next_page_s = resp.headers.get('X-Next-Page', 1)
while len(next_page_s) != 0:
next_page_i = int(next_page_s)
params['page'] = next_page_i
resp = request(url, params)
next_page_s = resp.headers.get('X-Next-Page', 1)
for row in resp.json():
yield row