[Tutor] renaming files within a directory

[Christian Witts]

davidwilson at Safe-mail.net wrote:
> Here is the updated viersion:
>
> ---
>
> import glob
> import csv
> from os import rename
>
>
> countries = {}
> reader = csv.reader(open("countries.csv"))
> for row in reader:
>     code, name = row
>     countries[name] = code
>
> files = set([file for file in glob.glob('Flag_of_*.svg')])
>
> for file in files:
>     file = file[8:-4]
>     if file.startswith('the_'):
> 	file = file[4:]
>     if countries.has_key(file):
> 	b = 'flag-'+ countries[file] + '.svg'
> 	print b
> 	rename(file, b)
>
> But I cannot get the rename to take effect and I get an error:
>
> $ python rename_svg.py 
> Uganda flag-ug.svg
> Traceback (most recent call last):
>   File "rename_svg.py", line 21, in <module>
>     rename(file, b)
> OSError: [Errno 2] No such file or directory
>
> What am I missing?
>
> -------- Original Message --------
> From: Kent Johnson <kent37 at tds.net>
> Apparently from: kent3737 at gmail.com
> To: davidwilson at safe-mail.net
> Cc: mail at timgolden.me.uk, tutor at python.org
> Subject: Re: [Tutor] renaming files within a directory
> Date: Mon, 27 Jul 2009 07:01:32 -0400
>
>   
>> On Mon, Jul 27, 2009 at 5:10 AM, <davidwilson at safe-mail.net> wrote:
>>
>>     
>>> files = set([file for file in os.listdir(os.getcwd()) if file.endswith('svg')])
>>> print len(files)
>>>
>>> for file in files:
>>>    file = file.strip('.svg')
>>>    print file
>>> #    if countries.has_key(file):
>>> #       print file
>>>
>>> When I run this I get:
>>>
>>> Flag_of_Uganda
>>> ...
>>>
>>> The problem is that for example the file Flag_of_the_United_States.svg when I use the strip('.svg') it is returned as Flag_of_the_United_State
>>>
>>> Also, How do I remove 'Flag_of', 'Flag_of_the_'
>>>       
>> I suggest you use glob.glob() instead of os.listdir():
>>
>> files = glob.glob('Flag_of_*.svg)
>>
>> Then you know that each file name starts with Flag_of_ and ends with
>> .svg. To remove them, since they are fixed strings you can just use
>> slicing;
>> file = file[8:-4]
>> if file.startswith('the_'):
>>   file = file[4:]
>>
>> Kent
>>     
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>   
You changed the name contained in file from the original so it now 
cannot find what you are referring to.  Try not to shadow built-in names 
like file by the way, it can cause unintended side-effects.

Make changes to this effect:

for filename in files:
    fn = filename[8:-4]
    if fn.startswith('the_'):
        fn = fn[4:]
    if fn in countries:   # Dictionaries can be accessed this way and it 
looks cleaner.
        new_filename = 'flag-%s.svg' % countries[fn]  # String 
formatting is neater and faster than concatenation
        rename(filename, new_filename)

-- 
Kind Regards,
Christian Witts