python - 尝试保存并写入文件

Question

while True: # Saving a file in txt file
    print("Would you like to save the latest generation? ('y' to save): ")
    saveInput = input()
    if saveInput == 'y' or saveInput == 'Y':
        print("Enter destination file name: ")
        fileName = input() 

        try:
            open(fileName, "r")
            close(fileName)
            print("Do you want to overwrite that file? ('y' to continue): ")
            confirm = input()

            if confirm == 'n':
                print("Enter destination file name: ")
                confirm2 = input()
                open(confirm2, 'w')

            elif confirm == 'y':
                open(confirm, 'w')
                for line in new_glider:
                    confirm2.writelines(new_glider)

                print(new_glider)



        except:
               break 

这是我到目前为止得到的，我试图首先读取一个文件，从中获取数据，然后通过我的程序运行它，最后询问他们是否要保存它，如果文件存在则询问是否他们想覆盖它，如果不创建一个新的，但是当我尝试输入目的地名称后它会跳过，如下所示:

输出

Enter input file name: 
g.txt

How many new generations would you like to print? 
4
Would you like to save the latest generation? ('y' to save): 
y
Enter destination file name: 
g.txt
>>>

有人能帮帮我吗？我已经坚持了一段时间

Answer 1

在您“尝试”打开文件的代码部分，文件尚不存在，因此它到达“except”部分(break)，程序终止。

     try:
            open(fileName, "r")
            close(fileName)
            print("Do you want to overwrite that file? ('y' to continue): ")
            confirm = input()

            if confirm == 'n':
                print("Enter destination file name: ")
                confirm2 = input()
                open(confirm2, 'w')

            elif confirm == 'y':
                open(confirm, 'w')
                for line in new_glider:
                    confirm2.writelines(new_glider)

                print(new_glider)

        except:
               break 

Replace it with os.path.isfile(fileName)

if os.path.isfile(fileName):
    print("Do you want to overwrite that file? ('y' to continue): ")
    confirm = input()

    if confirm == 'n':
        print("Enter destination file name: ")
        confirm2 = input()
        open(confirm2, 'w')

    elif confirm == 'y':
        open(**fileName**, 'w')

        for line in new_glider:
            confirm2.writelines(new_glider)

        print(new_glider)

# if fileName doesn't exist, create a new file and write the line to it.
else:
    open(**fileName**, 'w')

    for line in new_glider:
       confirm2.writelines(new_glider)

    print(new_glider)