string translate, replace, find and the forward slash

[destroooooy]

Hi folks,
I'm finding some (what I consider) curious behavior with the string
methods and the forward slash character. I'm writing a program to
rename mp3 files based on their id3 tags, and I want to protect
against goofy characters in the in tags. So I do the following:

unsafe_chars = "/#()[]!@$%^&*{}\'\"`?<>| \t\n"
alt_chars = "_________________________"

s_artist.translate(maketranstable(unsafe_chars, alt_chars))
which successfully replaces everything except for forward slashes (at
least in the files I've tested so far). If I use the "replace()"
method, it also does not work. Escaping the forward slash changes
nothing. "find()" however, works, and thus I've resorted to:

if "/" in s_artist:
(s_l, slash, s_r) = s_artist.partition("/")
s_artist = "_".join([s_l, s_r])

which is rather uncool. It works but I'd just like to know what the
deal is. TIA.

[Arnaud Delobelle]

destroooooy <de*********@gmail.comwrites:

Hi folks,
I'm finding some (what I consider) curious behavior with the string
methods and the forward slash character. I'm writing a program to
rename mp3 files based on their id3 tags, and I want to protect
against goofy characters in the in tags. So I do the following:

unsafe_chars = "/#()[]!@$%^&*{}\'\"`?<>| \t\n"
alt_chars = "_________________________"

s_artist.translate(maketranstable(unsafe_chars, alt_chars))
which successfully replaces everything except for forward slashes (at
least in the files I've tested so far). If I use the "replace()"
method, it also does not work. Escaping the forward slash changes
nothing. "find()" however, works, and thus I've resorted to:

if "/" in s_artist:
(s_l, slash, s_r) = s_artist.partition("/")
s_artist = "_".join([s_l, s_r])

which is rather uncool. It works but I'd just like to know what the
deal is. TIA.

It works fine here:

marigold:junk arno$ python
Python 2.5.1 (r251:54863, Jan 17 2008, 19:35:17)
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

>>unsafe_chars = "/#()[]!@$%^&*{}\'\"`?<>| \t\n"
table = range(256)
for c in unsafe_chars: table[ord(c)] = ord('_')

....

>>table = ''.join(chr(o) for o in table)
'Jon(&Mark/Steve)'.translate(table)

'Jon__Mark_Steve_'

>>>

--
Arnaud

[destroooooy]

On Apr 29, 4:50 pm, Arnaud Delobelle <[e-mail]:

destroooooy <[e-mail]:

Hi folks,
I'm finding some (what I consider) curious behavior with the string
methods and the forward slash character. I'm writing a program to
rename mp3 files based on their id3 tags, and I want to protect
against goofy characters in the in tags. So I do the following:

unsafe_chars = "/#()[]!@$%^&*{}\'\"`?<>| \t\n"
alt_chars = "_________________________"

s_artist.translate(maketranstable(unsafe_chars, alt_chars))

which successfully replaces everything except for forward slashes (at
least in the files I've tested so far). If I use the "replace()"
method, it also does not work. Escaping the forward slash changes
nothing. "find()" however, works, and thus I've resorted to:

if "/" in s_artist:
(s_l, slash, s_r) = s_artist.partition("/")
s_artist = "_".join([s_l, s_r])

which is rather uncool. It works but I'd just like to know what the
deal is. TIA.

It works fine here:

marigold:junk arno$ python
Python 2.5.1 (r251:54863, Jan 17 2008, 19:35:17)
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

>unsafe_chars = "/#()[]!@$%^&*{}\'\"`?<>| \t\n"
table = range(256)
for c in unsafe_chars: table[ord(c)] = ord('_')

...

>table = ''.join(chr(o) for o in table)
'Jon(&Mark/Steve)'.translate(table)

'Jon__Mark_Steve_'

--
Arnaud

Oooh. Let me try it that way.

[destroooooy]

On Apr 29, 4:50 pm, Arnaud Delobelle <[e-mail]:

destroooooy <[e-mail]:

Hi folks,
I'm finding some (what I consider) curious behavior with the string
methods and the forward slash character. I'm writing a program to
rename mp3 files based on their id3 tags, and I want to protect
against goofy characters in the in tags. So I do the following:

unsafe_chars = "/#()[]!@$%^&*{}\'\"`?<>| \t\n"
alt_chars = "_________________________"

s_artist.translate(maketranstable(unsafe_chars, alt_chars))

which successfully replaces everything except for forward slashes (at
least in the files I've tested so far). If I use the "replace()"
method, it also does not work. Escaping the forward slash changes
nothing. "find()" however, works, and thus I've resorted to:

if "/" in s_artist:
(s_l, slash, s_r) = s_artist.partition("/")
s_artist = "_".join([s_l, s_r])

which is rather uncool. It works but I'd just like to know what the
deal is. TIA.

It works fine here:

marigold:junk arno$ python
Python 2.5.1 (r251:54863, Jan 17 2008, 19:35:17)
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

>unsafe_chars = "/#()[]!@$%^&*{}\'\"`?<>| \t\n"
table = range(256)
for c in unsafe_chars: table[ord(c)] = ord('_')

...

>table = ''.join(chr(o) for o in table)
'Jon(&Mark/Steve)'.translate(table)

'Jon__Mark_Steve_'

--
Arnaud

Okay, so that definitely works. Thanks!

However, the chances of me coming up with that on my own were
completely nonexistent, and I'd still like to know how one would use
maketranstable() to get the same result...

[Arnaud Delobelle]

destroooooy <de*********@gmail.comwrites:

On Apr 29, 4:50 pm, Arnaud Delobelle <[e-mail]:

>>
marigold:junk arno$ python
Python 2.5.1 (r251:54863, Jan 17 2008, 19:35:17)
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

>>unsafe_chars = "/#()[]!@$%^&*{}\'\"`?<>| \t\n"
table = range(256)
for c in unsafe_chars: table[ord(c)] = ord('_')

...

>>table = ''.join(chr(o) for o in table)
'Jon(&Mark/Steve)'.translate(table)

'Jon__Mark_Steve_'

--
Arnaud

Okay, so that definitely works. Thanks!

However, the chances of me coming up with that on my own were
completely nonexistent, and I'd still like to know how one would use
maketranstable() to get the same result...

Do you mean maketrans() from the string module? I didn't know about
it, but I've tried it and it works too:

>>import string
unsafe_chars = "/#()[]!@$%^&*{}\'\"`?<>| \t\n"
alt_chars = "_________________________"
table = string.maketrans(unsafe_chars, alt_chars)
"a/b/c".translate(table)

'a_b_c'

>>>

--
Arnaud