time between blocks bsc

from web3 import Web3
import time


infura_url = "https://bsc-dataseed.binance.org/"
w3 = Web3(Web3.HTTPProvider(infura_url))


print(time.time())
lastb = w3.eth.block_number
lastt = time.time()
while True:
    t = time.time()
    b=w3.eth.block_number
    if lastb == b-1:
        print(t-lastt)
        lastb = b
        lastt = t