您的程序中有一个错误，语法无效python 2.7.15

Question

import urllib
import re

symbolslist = ["aaple", "spy", "goog", "nflx"]

i=0
while i<len(symbolslist):
   url = "http://finance.yahoo.com/q?s=" +symbolslist[i] +"&q1=1"
   htmlfile = urllib.urlopen(url)
   htmltext = htmlfile.read()
   regex = '<span id="yfs_184_'+symbolslist[i]'">(.+?)</span>'
   pattern = re.compile(regex)
   price = re.findall(pattern,htmltext)
   print "the price of", symbolslist[i]," is " ,price
   i+1

有人能告诉我上面的代码有什么问题吗？ 谢谢

Answer 1

您丢失了+符号：

regex = '<span id="yfs_184_'+symbolslist[i]'">(.+?)</span>'
                                          ^
                                          |
here                   -

Answer 2

使用format-it使代码更具可读性https://pyformat.info/

你错过了regex = '<span id="yfs_184_'+symbolslist[i]'">(.+?)</span>'的第二个+

import urllib
import re

symbolslist = ["aaple", "spy", "goog", "nflx"]

for symbol in symbolslist:
   url = "http://finance.yahoo.com/q?s={symbol}&q1=1".format(symbol=symbol)
   htmlfile = urllib.urlopen(url)
   regex = '<span id="yfs_184_{symbol}">(.+?)</span>'.format(symbol=symbol)
   pattern = re.compile(regex)
   price = re.findall(pattern, htmlfile.read())
   print("the price of", symbol," is " ,price)

Answer 3

线路

regex = '<span id="yfs_184_'+symbolslist[i]'">(.+?)</span>'

在symbolslist[i]之后需要+：

regex = '<span id="yfs_184_'+symbolslist[i]+'">(.+?)</span>'