在使用爬蟲是：from lxml import etree時報錯，沒有etree這個庫，這是因為有的lxml包中沒有整合etree
解決方法：可以自己再選擇安裝帶etree的lxml，我的Python是3.6，下載的etree是4.2.1
下載地址：https://www.lfd.uci.edu/~gohlke/pythonlibs/
下載後執行下圖程式碼不報錯說明安裝成功

etree使用程式碼例項（注：有時候匯入時飄紅並不程式碼出錯了）
import requests
import json
from lxml import etree

from selenium import webdriver
import requests
bro = webdriver.Firefox(executable_path = ‘D:\APPS\dir\geckodriver’)

d1 = open(‘etherscan_urls.json’,’r’).read()
d2 = json.loads(d1)
count = 0
for i in d2:
# d3 = requests.get(i)
bro.get(i)
selector = etree.HTML(bro.page_source)
data = selector.xpath(‘//*[@id=”ContentPlaceHolder1_divSummary”]/div[1]/table/tbody/tr[3]/td[2]/span/text()’)
data2 = selector.xpath(‘//*[@id=”ContentPlaceHolder1_divSummary”]/div[1]/table/tbody/tr[1]/td[2]/text()’)