Question

我得到一个超出范围错误的下标，我似乎无法通过某些原因通过，任何帮助将不胜感激？

我已经更改了变量以使其工作但仍然无法解决。由于某种原因，线程参数似乎没有考虑到我的两个变量

由于

from threading import Thread
import urllib.request
import re

    def th(ur):
        base = "http://finance.yahoo.com/q?s="+ur
        regex = '<span id="yfs_184_'+ur.lower()+'">(.+?)</span>'
        pattern = re.compile(regex)
        htmltext = urllib.request.urlopen(base).read().decode('utf-8')
        results = re.findall(pattern,htmltext)
        print ("the price of "+str(ur)+" is "+str(results[0]))


    symbolslist = ["aapl","goog"]

    print (symbolslist)

    threadlist = []

    for u in symbolslist:
        t = Thread(target = th, args= (u,))
        t.start()
        threadlist.append(t)

    for b in threadlist:
        b.join()

完整追溯：

C:\Python34\python.exe C:/Users/User/PycharmProjects/untitled/Hellopython.py
['aapl', 'goog']
Exception in thread Thread-1:
Traceback (most recent call last):
  File "C:\Python34\lib\threading.py", line 921, in _bootstrap_inner
    self.run()
  File "C:\Python34\lib\threading.py", line 869, in run
    self._target(*self._args, **self._kwargs)
  File "C:/Users/User/PycharmProjects/untitled/Hellopython.py", line 12, in th
    print ("the price of "+str(ur)+" is "+str(results[0]))
IndexError: list index out of range

Exception in thread Thread-2:
Traceback (most recent call last):
  File "C:\Python34\lib\threading.py", line 921, in _bootstrap_inner
    self.run()
  File "C:\Python34\lib\threading.py", line 869, in run
    self._target(*self._args, **self._kwargs)
  File "C:/Users/User/PycharmProjects/untitled/Hellopython.py", line 12, in th
    print ("the price of "+str(ur)+" is "+str(results[0]))
IndexError: list index out of range


Process finished with exit code 0

Answer 1

您的问题与多线程无关，只是因为results是一个空列表。正如评论所说，在打印前检查它的长度。

def th(ur):
    base = "http://finance.yahoo.com/q?s="+ur
    regex = '<span id="yfs_184_'+ur.lower()+'">(.+?)</span>'
    pattern = re.compile(regex)
    htmltext = urllib.request.urlopen(base).read().decode('utf-8')
    results = re.findall(pattern,htmltext)
    if len(results) > 0:
        print("the price of "+str(ur)+" is "+str(results[0]))
    else:
        print("results is empty")

IndexError：多线程时列出索引超出范围的错误

1 个答案: