UndefinedError: 'admin_base_template' is undefined - Flask Admin

02 Jan 2014 This happens when you try to render a template like this:
return render_template('admin/upload.html')

You need to use self.render instead:

return self.render('admin/upload.html')

Enable UART2 On BeagleBone Black for RS232 Cape

30 Dec 2013

Use this script to ensure UART2 is enabled in the device tree: https://github.com/victorporof/BeagleBone-SPI-UART
Enable ttyO1 it in the firmware using this guide (makes the device appear): http://www.element14.com/community/blogs/mirandasoft/2013/07/30/beaglebone-black-rapid-activation-of-ttyo1-ttyo2-ttyo4-and-ttyo5
Put a paperclip into the RS232 port like in the picture on this page: http://sensorsblog.com/serial-communications/rs232loopbacktest/
echo hello > /dev/ttyO1
cat /dev/ttyO1

Clustering With Leaflet

30 Dec 2013 http://jmduke.com/blog/2013/12/28/seattle-911

The Z Layout

29 Dec 2013 I'm definitely going to use this technique on my next business site: http://design.tutsplus.com/articles/understanding-the-z-layout-in-web-design--webdesign-28

Two Column Match - Flask + HandsOnTable

29 Dec 2013 I'm getting more comfortable with Flask, so I decided to experiment with Google App Engine + Flask + HandsOnTable.

Here's the application I made: http://twocolumnmatch.appspot.com/match

It takes the contents of the 2nd column and matches it to the rows of the first column. Just press the "Match" button to see what it does.

I've found myself doing what this application does a few times, but I manually create two python lists and compare them in IDLE. This application streamlines that process quite a bit.

Here's the code: https://github.com/pawl/2ColumnMatch

SQLalchemy - Simple Select Query

26 Dec 2013 from sqlalchemy import create_engine, MetaData, Table

engine = create_engine('sqlite:///cars.db', echo=False)
metadata = MetaData(bind=engine)

table = Table('cars', metadata)
stmt = table.select()
for row in stmt.execute():
print row

Entity-Attribute-Value - Dynamic Database Columns

26 Dec 2013 This page has a great example of when to use the Entity-Attribute-Value data model: http://stackoverflow.com/questions/7933596/django-dynamic-model-fields

I'm planning to use it for an application I'm making which has user defined fields.

SHOW COLUMNS or Get Column Names From SQLalchemy SELECT Query

18 Dec 2013

http://stackoverflow.com/questions/8947616/python-sqlalchemy-get-column-names-dynamically

Rob Wouter's answer really helped me out:

You can either find the columns by calling result.keys() or you can access them through calling v.keys() inside the for loop.
Here's an example using items():
for v in result:
for column, value in v.items():
print('{0}: {1}'.format(column, value))

AttributeError: 'dict' object has no attribute '_set_parent_with_dispatch' - SQLalchemy

11 Dec 2013

The documentation says: "Keyword arguments can be specified by specifying the last argument as a dictionary"

So you will need to change this:

__table_args__ = (

{'sqlite_autoincrement': True},

UniqueConstraint('filename', 'path')

)

to this:

__table_args__ = (
UniqueConstraint('filename', 'path'),
{'sqlite_autoincrement': True}

)

Flask-Admin Foreign Key Columns Allowing Editing

11 Dec 2013 Make sure you have a row id number as your primary key for your child table. Having a composite primary key didn't seem to save when I was editing the form.

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