CODEWITHSUNDEEP
pythonpython-3.xwindowsexception
Josh Sanders
Josh Sanders

Reputation: 756

Python 3 not raising exception for invalid file name

How can I get Python to raise an exception on opening a file with an invalid file name? Example, I have this code

def write_html_to_file(set_name, pid, html_text):
    if not os.path.exists(HTML_DUMP_DIR_NAME):
        os.makedirs(HTML_DUMP_DIR_NAME)
        path = (HTML_DUMP_DIR_NAME + set_name + '-' + pid + '.html')
    try:
        with open(path, "w+", encoding='utf-8') as html_dump_file:
            html_dump_file.write(html_text)
    except OSError as e:
        logging.basicConfig(filename=LOG_FILE_PATH, level=logging.ERROR)
        logging.error('Failed to create html dump. '
                      + ' error=' + e
                      + ' file_name=' + path)

Assume that the value of path is 'Folder1/SubFolder/Some Title: thing.html' and the file does not exist yet.

What I expect is that Python will raise an OSerror with Invalid Arguments, or something like that. What actually happens is it creates a file called 'Folder1/Subfolder/Some Title'. Notice the filename stops at the invalid character

I know I can create my own exceptions that I can raise if I detect an invalid name, but in this case that's pointless. I only care if I'm trying to do something invalid at the OS level. It seems in this case its failing silently and I don't like that.

Edit: Sorry, I guess my question wasn't clear.

Upvotes: 1

Views: 2171

Answers (1)

Josh Sanders
Josh Sanders

Reputation: 756

So it turns out (thanks eryksun), specifically the ':' in the string you pass to open() actually is a delimiter on NTFS systems that signifies that you want to write to multiple data streams:

My code works fine for any other character that is invalid in file names (* for example). So the solution I came up with is to replace any ':' in my filename with a - before I pass it to open()

base_file_name= base_file_name.replace(':', '-')

':'s are invalid in filenames anyway so this is fine for me.

Upvotes: 2

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