Author Archives: Yuji Tomita

Add the option ‘relative_urls’: ‘false’ to disable the auto absolute-to-relative link changing behavior.

This wiki lists all types of URL converting here… but I’m still having issues. I’ve tried all of them.

I’ve heard of issues with IE auto formatting links, but I’m using Chrome. I’m trying to write an img address for a newsletter, which will obviously fail if i use a relative link.

http://wiki.moxiecode.com/index.php/TinyMCE:FAQ#Paths.2FURLs_are_incorrect.2C_I_want_absolute.2Frelative_URLs.3F

WWaaait a minute.. Why doesn’t this link fail? >_>

/blah/ is reaching my server from refreshing gmail.. does it automatically determine the domain from email headers or something??

If you’re wondering how to run python.exe by typing python (like in a linux box), set up an environment variable called python that targets python.exe.

The following post details how to set an environment variable.
https://yuji.wordpress.com/2009/08/31/django-on-windows-setting-path-environment-variable/

Follow the instructions, except instead of appending to the Path variable, add a new one:

• Variable: python
• Value: C:\Python[version]\python.exe

Start up your command prompt and type ‘python’, or ‘python _whatever_’ and the commands should work as expected.

Here is an easy way to split a string in two. I just have a rudimentary form collecting a full name, yet my model stores first/last names.

I’m just going to use the partition string method.

‘Yuji Tomita’.partition(‘ ‘)
returns (‘Yuji’, ‘ ‘, ‘Tomita)

‘Yuji Middlename Tomita’.partition(‘ ‘)
returns (‘Yuji’, ‘ ‘, ‘Middlename Tomita’)

Which is plenty good for me.

I used this just the other day, with reference from its use in Satchmo payment processing to build a unique encrypted link for our affiliate clients.

I wanted them to have an easy, one click link that they can use to visit their information instead of having to remember a password (FAILS, unless service is important enough).

I used Blowfish in the Python Cryptography Toolkit.

import bas64from Crypto.Ciphers import Blowfish

encryption_object = Blowfish.new("my-key-of-some-kind") # keep this key.. I used the django settings.SECRET_KEY
encryption_object.encrypt() 

# requires multiple of 8 character input, so we must check if our string to encrypt is a multiple of 8 and add extra characters when it's short 
padding = ''
if (len(STRING_TO_ENCRYPT) % 8  ) <> 0    :  
    padding = 'X' * (8-(len(STRING_TO_ENCRYPT) % 8))  
    # len(STRING_TO_ENCRYPT) % 8 returns the remainder of division
    # subtracting this from 8 gives you the number needed to reach the multiple of 8.

encrypted_string = base64.b64encode(encryption_object.encrypt(STIRNG_TO_ENCRYPT+padding))
# b64encode to create a "more" url-safe string.


encryption_object.decode(base64.b64decode(encrypted_string)).rstrip('X') 

Now I can encrypt something like a slug and use it as a unique link that is only available to the person who I send the link to.

Another way I’ve done that is to use a 1 way hash: store a hash on the model of the slug and look up the DB object by hash.

I just didn’t want to add a new field and deal with updating DBs to add this feature.

This is a quick post about the standard library ‘csv’ in python. Absolute bare minimum usage to parse some CSV.

I’ve been using this or my own version of csv to process email lists, inventory histories, etc. Any time a spreadsheet is used, you can easily save it as a csv and load it up in python.

I do a lot of number crunching / processing that’s just too complicated to do easily in a spreadsheet, but data often comes in spreadsheets.

Example of usage in the python shell:

import csv
f = open('path/to/my/file', 'r') # open the file
reader = csv.reader(f)
reader.next() # prints the next ROW, as a list.
for row in reader:
         name = row[0]
         email = row[1]
         if email_validation(email): 
               #  do some logic to check against an ignore list, or what have you.
               save_email_or_smth(email, name)
f.close() # close the file.

Good god, I’ve casually wondered how to get to the end of the line in gnu screen for the emacs command ctrl + e without remapping it.

Turns out it’s pretty simple.. ctrl, ctrl+e.

Sweet!

Gnu Screen Bash: ctrl a + a = ctrl + a, and ctrl + e is the same.

Here’s a brute force method to force a unicode string to ASCII by removing all non ascii characters from a unicode string for those pesky Ordinal Not In Range errors or DB errors.

Though I found comprehensive solutions that replace the non ASCII characters and such with approximate values, I just wanted to get rid of them, ASAP, Yesterday.

''.join([x for x in 'YOUR_STRING' if ord(x) < 128])

For me, the cause of this error was sending arguments to the register function in the wrong order.

Check the order of registering a ModelAdmin: it’s the model class first, then the ModelAdmin class.

Example: admin.site.register(Model, ModelAdmin)

I suppose naturally the second one has to be the ModelAdmin since register(MyModel) works as well. That’s one good way to think about it.