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PR1000.10: Create a Basic "Password Counter" in Python 
A very enthusiastic Python 1000 student asked for the creation of a few more practice activities.

We decided to share our first design as an official project.


Destined to be the first in a series of follow-on activities for our increasingly popular Python 1000 & Python 2000 training opportunities, we hope other new Python students will enjoy the sharing, as well.



Sharing is caring!

-Rn

p.s: Those who need an introduction to the UML (at least enough to understand the above diagrams) might enjoy our YouTube UML Primer (video link).




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Backing Up Files Across Multiple Devices 
There you have them - sitting in a box. --From lots of CDs / DVDs, to far too many USB sticks to contemplate.

Rather than sitting there - waiting for us to toss them out - wouldn't it be nice if we could use them to backup our 'stuff?

Backup Splits


Much like in the days when we had lots of drive-tapes, the challenge is to split a `too-big` collection of files, across a `too-small` series of media. A problem almost as old as computing itself, fortunately all POSIX systems come with a program called `tar`!

sudo mkdir /d_backup 2> /dev/null
sudo chmod 777 /d_backup
cp $0 /d_backup
cd /d_backup
name=`date +d_drive_%Y_%j.tar`
echo Creating $name from $0
tar -cf ./$name /d_drive/
split -d -b 4480m ./$name

In the above, my task is to routinely back-up /d_drive into a folder named /d_backup. Once created, I want to split a julian-dated backup file into 4GB slices, from there to manually burn them out to a 2nd generation DVD drive. (*)

Splits Restored


To restore the files, all we need do is to (1) undo the `split,` by copying (2) all of the media-content to the hard drive, then (3) un-tar the concatenation:

cat * > d_drive.tar
tar xvf d_drive.tar

(*) Note that while the above `split` uses 4480 for the splits, that one should adjust the size to match the least-common size-denominator for any and all external media.



Sharing is caring!


-Rn



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FreeCAD: LED-Hacking an STL Figgurine 
The team & I had some fun over the weekend adding a coin-cell LED to a 3D model:


The challenge involved reverse engineering an STL so as to experiment with soft-drilling hex-holes, as well as using clear filaments.

The process was to import the STL, then rendering as a "mesh", so as to convert it to a "shape", then a "solid" in "Part" mode (phew!)

Fortunately, there is a plethora of information on how to do such things using FreeCAD.


(Yea - Testing GUI's is easy, by comparison =)

Then, of course, we had to "map" a "sketch" to the solid in "Part Design" mode so as to start soft-drilling the thing to accept a standard sized CR2032 coin cell battery, plus either a 5 or 6mm LED.



The neat discovery de-jure was centered around how using faceted drill holes scatter light far more brilliantly (pun intended) than simply drilling things out.

So if you have a 3D printer, then feel free to give our "Mr. Moai" remix a try. For best results:

(1) Rotate & print on the base. (No supports required!)
(2) Use 0% infill.
(3) Set your wall size to 4x your nozzle size. (e.g. Our 0.4mm nozzle meant that we used a 1.6mm wall size.)

--You could even have them print one up for you!


Enjoy,


-Rn

p.s: A few days later, we remixed another - this time with a video to show off the internal wire frame.

Unlike the above, this one allows several Moai to be wired together in a series.


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