[Tutor] renaming files within a directory

[Christian Witts]

davidwilson at Safe-mail.net wrote:
> Here is what I have so far:
>
> import os
> import csv
>
> countries = {}
> reader = csv.reader(open("countries.csv"))
> for row in reader:
>     code, name = row
>     countries[name] = code
>
> 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
> Flag_of_the_United_State
> Flag_of_Abkhazia
> Flag_of_Montenegro
> Flag_of_Qatar
> Flag_of_Gabon
> Flag_of_Uzbekistan
> Flag_of_Kiribati
> Flag_of_Armenia
> Flag_of_Panama
> Flag_of_Monaco
> Flag_of_Australia
> Flag_of_Liechtenstein
> Flag_of_Tunisia
> Flag_of_Georgia
> Flag_of_Palau
> Flag_of_the_Central_African_Republic
> ...
>
> 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 guess after this I can compare the value with the key and map the tld?
>
> Or is it better to use regex and then search from the list of countries? But how???
>
> -------- Original Message --------
> From: Tim Golden <mail at timgolden.me.uk>
> Apparently from: tutor-bounces+davidwilson=safe-mail.net at python.org
> To: 
> Cc: tutor at python.org
> Subject: Re: [Tutor] renaming files within a directory
> Date: Sun, 26 Jul 2009 20:41:10 +0100
>
>   
>> davidwilson at Safe-mail.net wrote:
>>     
>>> OK I am lost ;(
>>>
>>> I changed the code to:
>>>
>>>       
>>>>>> reader = csv.reader(open("countries.csv"),  delimiter=";")
>>>>>> for row in reader:
>>>>>>             
>>> ...     print row 
>>> ... 
>>> ['bi', 'Burundi']
>>> ['km', 'Comoros']
>>> ['dj', 'Djibouti']
>>> ['er', 'Eritrea']
>>>
>>> ...
>>>
>>> Now each row is a list with two items each.
>>>
>>> But when I do this:
>>>
>>>       
>>>>>> dic = []
>>>>>> for row in reader:
>>>>>>             
>>> ...         newdic.append({row[0]: row[1]})
>>> ... 
>>>       
>>>>>> dic
>>>>>>             
>>> []
>>>
>>> I get an empty dictionary
>>>       
>> Well, you actually get an empty list :)
>> To instantiate an empty dictionary, you use curly brackets:
>>
>> d = {}
>>
>> To add something to a dictionary, you use:
>>
>> d[<key>] = <value>
>>
>> Try something like this:
>>
>> <code - untested>
>> import csv
>>
>> reader = csv.reader(open("countries.csv"),  delimiter=";")
>> countries = {} # note the curly brackets
>> for row in reader:
>>    code, name = row # handy Python tuple unpacking
>>    countries[name] = code
>>
>> </code>
>>
>>
>> Once you're used to the idea, you can get reasonably slick
>> with dictionary initialisers and generator expressions:
>>
>> import csv
>>
>> reader = csv.reader(open("countries.csv"),  delimiter=";")
>> countries = dict ((row[1], row[0]) for row in reader)
>>
>> And once you're really confident (and if you're a
>> fan of one-liners) you can get away with this:
>>
>> import csv
>> countries = dict (
>>    (name, code) for \
>>      (code, name) in \
>>      csv.reader (open ("countries.csv"), delimiter=";")
>> )
>>
>>
>> BTW, I tend to open csv files with "rb" as it seems to
>> avoid line-ending issues with the csv module. YMMV.
>>
>> TJG
>> _______________________________________________
>> Tutor maillist  -  Tutor at python.org
>> http://mail.python.org/mailman/listinfo/tutor
>>     
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>
>   
Strip will remove those characters until it hits a character not in the 
set.  You could use file.split('.svg')[0]

-- 
Kind Regards,
Christian Witts