使用Python从文件读取

Question

I was wondering if somebody could help me out with the following Python 3 code. For some reason it is not doing what I believe it should be doing and I cannot understand why.

with open("ModuleShow.txt", "w+", encoding='utf-8') as ModuleShowFile:
            if ModulesLeft == 0:
                ModuleLoaded = CommandLine[2]
                print(ModuleLoaded)
            else:
                ModuleLoaded = ModuleToLoad[0]
                ModuleToLoad.pop(0)
                ModulesLeft = ModulesLeft - 1
                #            ModuleFile.write("\n" + ModuleLoaded)                                                    
                #            CommandsFile.write("module show" + ModuleLoaded)                                         
            output = subprocess.Popen(["bash", "-ci", "module show " + ModuleLoaded], stderr=ModuleShowFile)

#            with open("ModuleShow.txt", "r", encoding='utf-8') as ModuleShowFile:                                        

            print(ModuleShowFile.read())
            for ModuleFileLine in ModuleShowFile:
                FileLine = ModuleFileLine.split(" ")

                print(FileLine[0])
                if FileLine[0] == "prepend-path":
                    print(FileLine[0])
                    if FileLine[1] == "PATH":
                        ModulePathFile.write(FileLine[2] + " " + ModuleLoaded + "\n")
                    elif FileLine[0] == "module":
                        ModuleToLoad.append(FileLine[2])
                        ModulesLeft = ModulesLeft + 1

So what I am doing in the above code is writing information to a file called ModuleShow.txt and then parse that information and writing the parsed information to a file called ModulePath.txt, I opened the ModulePath.txt before, but I did not include that part of the code since I believe it is not related to the problem I am having.

So basically, when I run my script, the contents are written to the file, but I do not get anything when I read the contents. For example, I tried using "print(ModuleShowFile.read())," but nothing prints yet the file gets created with the contents inside. I tried having two "with open()" lines, one for writing and another for reading, but it still did not solve the problem. Hopefully it is something simple and I apologize for the long post. I would greatly appreciate any help. Thank you.

Answer 1

Do you even need to write the file ModuleShow.txt? Or can you just hold the entries in a list?

If you really need to read them back in again, close the file first, like this:

with open("ModuleShow.txt", "w+", encoding='utf-8') as ModuleShowFile:
    # ... whatever (I'm assuming you're writing to the file here)

# now the file is closed
with open("ModuleShow.txt", "r", encoding='utf-8') as ModuleShowFile:
    for ModuleFileLine in ModuleShowFile:
        # ... now you can read each line