Python - 如何停止循环

Question

我有这个，它读取一个名为 source1.html、source2.html、source3.html 的文件，但是当它找不到下一个文件(因为它不存在)时，它会给我一个错误。可以有 x 数量的 sourceX.html，所以如果找不到下一个 sourcex.html 文件，我需要说些什么，停止循环。

Traceback (most recent call last): File "main.py", line 14, in file = open(filename, "r") IOError: [Errno 2] No such file or directory: 'source4.html

如何停止脚本寻找下一个源文件？

from bs4 import BeautifulSoup
import re
import os.path

n = 1
filename = "source" + str(n) + ".html"
savefile = open('OUTPUT.csv', 'w')

while os.path.isfile(filename):

    strjpgs = "Extracted Layers: \n \n"
    filename = "source" + str(n) + ".html"
    n = n + 1
    file = open(filename, "r")
    soup = BeautifulSoup(file, "html.parser")
    thedata = soup.find("div", class_="cplayer")
    strdata = str(thedata)
    DoRegEx = re.compile('/([^/]+)\.jpg')
    jpgs = DoRegEx.findall(strdata)
    strjpgs = strjpgs + "\n".join(jpgs) + "\n \n"
    savefile.write(filename + '\n')
    savefile.write(strjpgs)

    print(filename)
    print(strjpgs)

savefile.close()
print "done"

Answer 1

使用 try/except 和 break

while os.path.isfile(filename):
    try:  # try to do this
         # <your code>
    except FileNotFoundError:  # if this error occurs
         break  # exit the loop

您的代码当前无法运行的原因是您正在检查 while 循环中是否存在 previous 文件。不是下一个。因此你也可以这样做

 while True:
     strjpgs = "Extracted Layers: \n \n"
     filename = "source" + str(n) + ".html"
     if not os.path.isfile(filename):
          break
     # <rest of your code>