On Thu, Jun 16, 2016 at 10:38:13AM -0500, boB Stepp wrote:
> I am extremely gradually trying to dip my big toe into the waters of
> writing classes.
[...]
> What I learned today:
>
> 1) FTP from ftplib appears to be an old-style class.
>
> 2) I can't just use "class FTPFiles(FTP)" or I will be using old-style
> classes.
>
> 3) I need to use "class FTPFiles(FTP, object)" to use new-style
> classes and "object" must come AFTER "FTP".
>
> 4) I have to use "super(FTPFiles, self).__init__(host, user, passwd)"
> or I cannot successfully inherit from the FTP() class. Also, "self"
> apparently must come AFTER "FTPFiles" in the super expression.
>
> Questions:
>
> 1) Are there any more common "gotchas" that might be coming my way in
> trying to use a new-style class inheriting from an old-style class in
> ancient Py 2.4.4?
That's a very interesting question. I *think* the answer is "No", but I
wouldn't put money on it.
> 2) I don't have much knowledge about FTP processes. This is being
> used on a secure intranet environment. And I am using the ftplib for
> the first time. In its docs it mentioned that the quit() method is
> the "polite" way to close the connection, but that an exception may be
> raised if the responds with an error to the "QUIT" command the method
> sends. If this happens, will the connection close?
According to the source code, yes.
> Or should I do something like:
>
> try:
> ftp.quit()
> except:
> ftp.close()
>
> ? It seems here (If I should use the "try" block.) that a bare
> "except" is appropriate as I would think I would want to close the
> connection regardless of the type of error the "QUIT" command
> generates.
Bare except is nearly never appropriate. Consider:
try:
fpt.quit()
except:
ftp.close()
> 3) The point of the print_welcome_msg() method is to be sure that I
> have actually successfully connected to the FTP server. Is there a
> better way to check for connection success?
If the connect method doesn't raise an exception, it connected
successfully.
--
Steve
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