为什么我的程序在编写Stocks.txt时跳过最后一个元素(tesla)？

Question

我只是想知道，为什么我的程序，即使它找到了数据，不能写特斯拉的数据，即使它写的每一个股票的数据。这是我的代码：

import requests, bs4, logging

stocks = {"google":"694653","amazon":"660463","apple":"22144","hack":"898127760101820","facebook":"296878244325128",
          "biotech":"700203","construction":"705971","nvidia":"662925","netflix":"672501","tesla":"12607212","":""}

new = open("Stocks.txt","w")

for stock in stocks:

    website = requests.get("https://www.google.ca/finance?cid=" + stocks[stock])
    website.raise_for_status()

    html = bs4.BeautifulSoup(website.text,"html.parser")

    price = (html.select(("#ref_%s_l") % stocks[stock])[0]).getText()
    change = (html.select(("#ref_%s_cp") % stocks[stock])[0]).getText()

    today = open("Stocks.txt","a")
    today.write(stock + ": " + price + "  " + change + 2*"\n")

Answer 1

避免此类文件关闭问题的一个好方法是使用with构造：

例如，替换

new = open("Stocks.txt","w")

使用

with open("Stocks.txt","w") as new:
    new.write ("XXX")
    #you can do all kinds of stuff here

这将在您完成缩进部分之后自动关闭文件。您可以在这个这里和这个所以问题上阅读。