关闭文件时的I/O操作错误

Question

我正在写一个程序，用来读取文件，使用的是open()这个函数。当我尝试运行程序时，出现了一个错误：ValueError: I/O operation on closed file（在第18行）。

我在网上看到的关于这个问题的每个提问，问题总是和缩进有关。也就是说，试图在一个没有在同一个循环中打开的文件上进行操作。我对Python有点生疏了，但我觉得我的缩进看起来没问题。

我希望有人能帮我快速看一下，告诉我缩进是否有问题，或者是不是还有其他原因导致这个错误？以下是代码（错误部分已注释）：

sourceFile = 'test.html'
serviceTarget = "Plumbers & HVAC Experts"
cityTarget = "NJ"

services = {"Plumbers", "Air Conditioning Experts", "Drain Cleaning Experts"}
cities = {"Westfield", "Scotch Plains", "Clark"}

serviceNames = {"Plumbers":"plumbers", "Air Conditioning Experts":"ac", "Drain Cleaning Experts":"drain"}
totalPages = len(services)*len(cities)

for serviceRep in services:
    for cityRep in cities:
        outFileName = cityRep + " " + serviceNames[serviceRep] + ".html"
        outFileName = outFileName.replace(" ", "_");
        print("Writing " + outFileName + "...")
        infile = open(sourceFile)
        outfile = open(outFileName, 'w')
        for line in infile:   #This is the line giving me problems
            if serviceTarget in line:
                line = line.replace(serviceTarget,serviceRep)
            if cityTarget in line:
                line = line.replace(cityTarget,cityRep)
            outfile.write(line)
            infile.close()
            outfile.close()
        totalPages -= 1; 
        print("DONE -- " + str(totalPages) + " left to go")

Answer 1

看起来像是缩进的问题：你真的想让 infile.close() 和 outfile.close() 这两行代码在 for line in infile: 这个循环里面吗？