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Archive for August, 2011

Djangoappengine – setting up

August 19, 2011 Leave a comment

Objective:
Set up djangoappengine.

Steps:
1. Download appengine from http://code.google.com/appengine/downloads.html. (I am using Google App Engine SDK for Python – Linux/Other Platforms)
2. Download djangoappengine http://www.allbuttonspressed.com/projects/djangoappengine. The instructions on how to install are on the same page.
3. From the djangoappengine page.

Copy the following folders into your project (e.g., django-testapp):

* django-nonrel/django => /django
* djangotoolbox/djangotoolbox => /djangotoolbox
* django-autoload/autoload => /autoload
* django-dbindexer/dbindexer => /dbindexer
* djangoappengine => /djangoappengine

That’s it. Your project structure should look like this:

* /django
* /djangotoolbox
* /autoload
* /dbindexer
* /djangoappengine

Copy the folders from the zipped files into you django-testapp folder so that you have the same project structure as above. (In my case project was simply the django-testapp folder).

4. Within django-testapp folder run

user@computer:~$ cd /home/user/google_appengine/django-testapp
user@computer:~/google_appengine/django-testapp$python2.5 manage.py runserver 127.0.0.1:8021
The Google App Engine SDK could not be found!
Make sure it's accessible via your PATH environment and called google_appengine.

5. I needed to add google_appengine to where djangoappengine would find it.
From what I could tell, djangoappengine looks for google_appengine in various folders one of them being /usr/local/google_appengine. So I simply created a symbolic link to that folder. I had installed google_appengine in /home/user/google_appengine. So as root I created a symbolic link.

root@computer:~# ln -s /home/user/google_appengine /usr/local/google_appengine

6. Within django-testapp folder run

user@computer:~/google_appengine/django-testapp$python2.5 manage.py runserver 127.0.0.1:8021
WARNING:root:No ssl package found. urlfetch will not be able to validate SSL certificates.
WARNING:root:Could not read datastore data from /home/user/google_appengine/django-testapp/.gaedata/datastore
INFO:google.appengine.tools.appengine_rpc:Server: appengine.google.com
WARNING:root:Could not read datastore data from /home/user/google_appengine/django-testapp/.gaedata/datastore
INFO:root:Connecting to SQLite database '' with file '/home/user/google_appengine/django-testapp/.gaedata/rdbms'
INFO:root:Running application ctst on port 8021: http://127.0.0.1:8021

NB. I am ignoring the warnings for now. I will post again once I figure out how to sort them out.

7. Open a browser and go to http://127.0.0.1:8021/.

djangoappengine

If you get the above screen shot then you are good to go.

Update (15th September 2011):
1. The data store warning should go once you add data to your datastore.
2. For the follwing warning

WARNING:root:You are using the default Django version (0.96). The default
Django version will change in an App Engine release in the near future.
Please call use_library() to explicitly select a Django version. For more
information see
http://code.google.com/appengine/docs/python/tools/libraries.html#Django

Add to main.py as per app.yaml. In my case it is

– url: /.*
script: djangoappengine/main/main.py

os.environ[‘DJANGO_SETTINGS_MODULE’] = ‘settings’

from google.appengine.dist import use_library
use_library(‘django’, ‘1.2’)

But when I do that I get this error

UnacceptableVersionError: django 1.2 was requested, but 1.3.0.final.0 is already in use

When I set it to use_library(‘django’, ‘1.3’) I get

ValueError: 1.3 is not a supported version for django; supported versions are [‘0.96’, ‘1.0’, ‘1.1’, ‘1.2’]

So I am ignoring the warning and not adding use_library to my main.py.

Categories: django Tags: ,

bash – working with spaces

August 16, 2011 Leave a comment

Problem:
Have bash ignore the spaces between words when looping through a file.

Eg

shell> cat model_country.txt
Toyota / Japan
Subaru / Japan
Audi / Germany

shell>for list in $(cat model_country.txt);do echo $list; done
Toyota
/
Japan
Subaru
/
Japan
Audi
/
Germany

Solution:
1. Change IFS

shell>export IFS=$'\n'

shell>for list in $(cat model_country.txt);do echo $list; done
Toyota / Japan
Subaru / Japan
Audi / Germany

Source:
http://blog.ynema.com/?p=260

NB. No need to change IFS back to ‘ \t\n’ as changes made in the example above are lost once the terminal is closed.

2. Use read

shell>cat model_country.txt | while read list; do echo $list; done
Toyota / Japan
Subaru / Japan
Audi / Germany

Source:
http://sandrylogan.wordpress.com/2011/06/10/line-by-line-in-bash-coping-with-the-spaces/

Categories: bash Tags: , ,

sed – substituting certain text

August 15, 2011 Leave a comment

Problem:
Substitute text in a file only for lines that contain a certain word.

Solution:
# substitute “foo” with “bar” ONLY for lines which contain “baz”
sed ‘/baz/s/foo/bar/g’

Source:
http://www.eng.cam.ac.uk/help/tpl/unix/sed.html

How I used it.
From

Date Total
2011-08-01 15,355
2011-08-02 16,799
2011-08-03 26,521
2011-08-04 41,876
2011-08-05 12,690
2011-08-06 19,489

The raw html. Saved as Aug2011_totals.html

<table>
<tr style="background-color:black;font-family:sans-serif;color:white;font-weight:bold;"><td>Date</td><td>Total</td></tr>
<tr style="background-color:#85c6ef;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-01</td><td>15,355</td></tr>
<tr style="background-color:#d0e3ef;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-02</td><td>16,799</td></tr>
<tr style="background-color:#85c6ef;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-03</td><td>26,521</td></tr>
<tr style="background-color:#d0e3ef;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-04</td><td>41,876</td></tr>
<tr style="background-color:#85c6ef;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-05</td><td>12,690</td></tr>
<tr style="background-color:#d0e3ef;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-06</td><td>19,489</td></tr>

</table>

To

Date Total
2011-08-01 15,355
2011-08-02 16,799
2011-08-03 26,521
2011-08-04 41,876
2011-08-05 12,690
2011-08-06 19,489

The raw html

<table>
<tr style="background-color:black;font-family:sans-serif;color:white;font-weight:bold;"><td>Date</td><td>Total</td></tr>
<tr style="background-color:#85c6ef;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-01</td><td>15,355</td></tr>
<tr style="background-color:#f60516;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-02</td><td>16,799</td></tr>
<tr style="background-color:#f60516;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-03</td><td>26,521</td></tr>
<tr style="background-color:#d0e3ef;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-04</td><td>41,876</td></tr>
<tr style="background-color:#85c6ef;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-05</td><td>12,690</td></tr>
<tr style="background-color:#d0e3ef;font-family:sans-serif;text-align:right;"><td style="font-weight:bold;">2011-08-06</td><td>19,489</td></tr>

</table>

The dates to be highlighted in red may change and to prevent someone from “breaking” something when editing the raw html, it was decided to put the dates in a text file then use sed to make the change to the html file.

shell> less highlighted_dates.txt
2011-08-03
2011-08-02

To do the hightlighting based on the dates in the file. I used sed and bash. This can be then saved as a bash script.

shell> for date_ in $(cat highlighted_dates.txt); do sed -e "/$date_/s/\#85c6ef/\#f60516/" -e "/$date_/s/\#d0e3ef/\#f60516/" Aug2011_totals.html > Aug2011_totals.html.tmp && mv Aug2011_totals.html.tmp Aug2011_totals.html; done
Categories: bash Tags: ,