用于搜索 url 的 Python 代码

Question

嘿，所以我试图获取当前的油价，然后对其进行一些数学计算以进行硬件作业。我无法在网站上找到我需要的号码。 这是我的代码

    # Module oilcost.py to compute the delivery cost for home heating oil.
# Assume your delivery company charges a 10% fee on top of the price 
# per gallon.  The module should take one command line argument 
# indicating the number of gallons needed and should output the 
# total cost.

import sys
import re
import urllib



def getOilPrice(url):
    f = urllib.urlopen(url)
    html=f.read()
    f.close()
    match = re.search(r'<span class="dailyPrice">( d+.? d+)</span>', html)
    return match.group(1) if match else '0'

def outputPrice(oilprice, gallons, total):
    print 'The current oil price is $ %s' %oilprice


def main():
    url = 'http://www.indexmundi.com/commodities/?commodity=heating-oil'
    oilprice = float(getOilPrice(url))     # Create this method
    gallons = float(sys.argv[1])                      # Get from command line
    total = (gallons * 1.1) * oilprice
    outputPrice(oilprice, gallons, total)  # Create this method
if __name__ == '__main__':
    main()

谁能告诉我我做错了什么？

Answer 1

Parsing html is notiorusly fraught with peril;但对于家庭作业来说，这可能并不那么重要；这是学习正则表达式的好机会。

上线:

match = re.search(r'<span class="dailyPrice">( d+.? d+)</span>', html)
#                                              ^    ^

你有一些d，它们将与文字字母d匹配。您的意思可能是 \d (这是一个反斜杠)吗？