python3; ftplib: TypeError: Can't convert 'bytes' object to str implicitly

[MRAB]

On 2014-05-14 19:06, Antoon Pardon wrote:
> op 14-05-14 18:24, Akira Li schreef:
>> Antoon Pardon <antoon.pardon at rece.vub.ac.be> writes:
>>
>>> This is the code I run (python 3.3)
>>>
>>> host = ...
>>> user = ...
>>> passwd = ...
>>>
>>> from ftplib import FTP
>>>
>>> ftp = FTP(host, user, passwd)
>>> ftp.mkd(b'NewDir')
>>> ftp.rmd(b'NewDir')
>>>
>>> This is the traceback
>>>
>>> Traceback (most recent call last):
>>>   File "ftp-problem", line 9, in <module>
>>>     ftp.mkd(b'NewDir')
>>>   File "/usr/lib/python3.3/ftplib.py", line 612, in mkd
>>>     resp = self.voidcmd('MKD ' + dirname)
>>> TypeError: Can't convert 'bytes' object to str implicitly
>>>
>>> The problem is that I do something like this in a backup program.
>>> I don't know the locales that other people use. So I manipulate
>>> all file and directory names as bytes.
>>>
>>> Am I doing something wrong?
>>
>> The error message shows that ftplib expects a string here, not bytes.
>> You could use `ftp.mkd(some_bytes.decode(ftp.encoding))` as a
>> workaround.
>
> Sure but what I like to know: Can this be considered a failing of
> ftplib. Since python3 generally allows paths to be strings as
> well as bytes can't we expect the same of ftplib?
>
> Especially as I assume that path will be converted to bytes anyway
> in order to send it over the network.
>
 From studying the code, I see that it uses the Latin-1 encoding.

On another note, I find it interesting that the default for the timeout
argument uses the 'magic' value -999 rather than, say, None!