Learning Flask with Corey Schafer

My Summer project is to finish an initial version of my Practice Math site for our kids. I’ve hit a bit of a snag with fractions, but the functionality for whole numbers is almost ready.

The next step is to create a web site for the project so our kids can use the app through their browsers, rather than using the command line (somehow, I don’t think a CLI interface will grab our kids).

My plan was to learn Django, and use that to create a front-end for my Python back-end. I decided to follow along with Brad Traversy to help me learn how to create a basic Django app. It was a little trickier than I expected, and I hit a snag with my database configuration.

I then thought I’d take a look at Flask, and see if that would be a little easier for me to grok. I noticed that Corey Schafer has a Flask tutorial series where you build a basic blog with Python and Flask, so I decided to work through Schafer’s tutorial videos.

This has proven to be a terrific idea. Schafer’s tutorials are detailed, and really clear. There are times when he speeds up a little but, for the most part, I can follow along pretty comfortably, and understand what he’s doing.

Even though the goal of Schafer’s series is to build a blog, it covers a range of topics that I can incorporate into Practice Math down the line. It’s really an awesome introduction to building web sites with Flask, and well worth the time.

Not only does Schafer take you through the process, step-by-step, but he also provides links to snapshots of his code at each step of the process, along with useful code snippets in his GitHub repos.

You probably need about an hour for each episode. I binged for most of today (I’m on vacation this week), and worked through about four or five videos.

If you’re interested in Corey Schafer, listen to this TalkPython interview with him:

On a related, side note, working through this tutorial series just reinforces how glad I am that I returned to Python to start learning it (again). I still have a long way to go, but it feels like I’m picking up bits of it easier than I did with JavaScript.

I’ll return to JavaScript, for sure (you can’t really ignore JavaScript these days). For now, though, I love all the things I’m learning to do with Python.

Featured image by Sharon McCutcheon

Practice Math – the Python Edition

One of my projects this Summer is to create a working version of my Practice Math project. The goal of this project is to create a site that my kids can use to practice their math.

The idea was to create a simple site that would randomly generate math equations that kids could use to practice addition, subtraction, multiplication, and division. To do this, the site would need to have the following functions, at least in the first phase of my project:

  1. Randomly generate two numbers, and a math operator to create an equation;
  2. Evaluate the solution to the equation;
  3. Prompt the child to offer an answer to the equation;
  4. Compare the child’s answer with the actual solution, and give feedback;
  5. Make sure that equations don’t produce negative solutions (our kids haven’t really learned how to work with numbers less than zero); and
  6. Round answers to two decimal places (it can be more than this, I just picked two decimal places for now).

Version 1 – the Javascript Edition

My initial version of the project was based on Javascript. You can find that one here, on GitHub. I wasn’t able to make much progress beyond randomly generating the numbers and math operators that would be used in equations.

I hadn’t worked out how to evaluate the randomly generated numbers, more move much beyond point two in my list of features. I’m certain it’s possible, I just hadn’t worked it out yet.

Version 2 – the Python Edition

I recently decided to return to learning Python. I last attempted to learn Python about a year and a half ago. At the time, I was learning Python 2.7.x. I didn’t move beyond loops at the time.

This time, I decided to start with Python 3.x, which is the current version. I’ve been learning when I have time, and I really like the language. I decided to revisit my Practice Math project and create a Python version to help me learn the language.

I finally sat down this morning, and worked on a script that does all six of the things I want it to do. I’ve published my code on GitHub, here. Here it is in action:

I can’t take credit for what you see there, not entirely. I borrowed pretty heavily from a few sources to produce the version you see there:

Cory Kramer’s solution (the third one in this list) was particularly helpful because it helped me split my code into disparate functions. This makes the script a lot easier to read, and tweak.

My current code still has some test stuff in it. For example, the script current prints the two generated numbers, the operator, and the solution so I can check that it’s all working properly:


print("\nThis is for troubleshooting purposes only:")
print(num1) # For testing
print(num2) # For testing
print(op) # For testing
print("\nWhat is {} {} {}? > ".format(num1, op, num2))
solution = round(eval(f"{num1} {op} {num2}"), 2)
print(solution) # For testing

Next steps

The next step is to create a web interface for this. A command line version is fine to play around with, but for this to be useful, it needs to be a web site. I haven’t worked out how to add a Javascript front-end to this (I believe it’s possible, I have no idea how to do it, though).

What I’ll rather do, though, is use a Python web framework like Django to create a front end for the site. I’m really keen to learn how to do that, partly because I want to port my Modiin Bus project over to Python too at some point (I discovered that the transit data that I’d like to use is available through Python APIs).

At the same time, I also intend figuring out how to represent fractions in the web interface. I know that’s it’s possible to use Javascript to represent fractions on a web page using options such as math.js and MathJax. I’ll look for equivalent options for Python/Django.

There are also a couple niggling issues about the current version that I’d like to resolve too. These likely exist because I’m still very much a Python newbie.

I’m sure there are other improvements I could make to how the script accepts, and processes input from users. I’ll figure that stuff out as I go. For now, I’m pretty please that this core script seems to be working.

My idea of a good time: coding on a Linux computer

Lately my idea of fun has been firmly rooted in coding, and playing around with Linux.

We’re planning to buy our son a new Linux PC after passing his (and before him, my) old Linux PC to our daughter.

I’m very tempted to extend my loan of my personal MacBook Air to him, and but myself a new laptop to install Linux on, and use that to explore what’s possibly my latest midlife crisis.

This article about Jason Evangelho’s switch to Linux just reinforces my temptation/idea.

Canonical’s Ubuntu seems to command a lot of mindshare when it comes to desktop Linux, so that was my next stop. I went through the same paces: download to a USB stick, boot up to the “Live” version of Ubuntu 18.04 (which includes 5 years of security patches and updates), have a look around, click “Install.” Ubuntu presented me with several options for partitioning the internal SSD, including blasting the entire drive. Tempting! I was feeling lucky so I took the plunge.

Raising brave, imperfect daughters, and teaching them to code

Last week I came across a tweet sharing Reshma Saujani’s TED talk, titled “Teach girls bravery, not perfection“. I immediately bookmarked it to watch with my daughter (and tweeted my plan to do that).

Saujani replied to my tweet, and asked me to let her know what my daughter thought of the talk.

So, I watched the talk on Saturday morning with my 7 year old (along with my son). Afterwards, I asked her what she thought about what Saujani said about how important it is to be brave, rather than being perfect, and how the quest for perfection is so self-defeating.

My daughter said she liked the video. I asked her to elaborate, and she commented on this talk has inspired her to try to learn to code again. She said that she stopped trying the first time around because she kept making mistakes.

I noticed this when I introduced her to coding on Code.org last year. She started off really excited to see what she could create after watching me learn front-end web development for most of last year. But she soon gave up when the exercises became trickier and she found herself making mistakes.

Since watching the talk, she’s been asking me when she can get back to learning to code. It also helps that my son has also returned to learning to code after seeing me return to Python (I’ve started at the beginning with Python 3).

Now all I need to do is pick a learning platform for her to learn with. So far, Code.org and Scratch look like good options for her.

Photo by Jelleke Vanooteghem on Unsplash

The life of a coder in gifs

The life of a coder/developer is both a wonderful and immensely frustrating experience. The scales tip in both directions, usually several times a day.

Today was no exception. I’ve been stuck on something for the last few days. My code should have been working, but it didn’t. If I had hair to spare, I’d probably have torn some of it out in frustration.

Animated frustration
That feeling, after a few days of trying to find the bug in my code.

Of course, as these things tend to go, I found the reason why my code wasn’t working. It was a typo. A single letter that shouldn’t have been there.

Relief, and annoyance
Oh man, THAT broke my code and left me frustrated and confused for 2 days?

My sense of relief is somewhat moderated by my amazement at how I missed it.

But, on the other hand, I found the bug! Now on to the next new code and the next bug.

Making sense of JavaScript array methods with Array Explorer

Sarah Drasner shared her awesome Array Explorer tool on Twitter the other day. It’s design is pretty simple, and yet a powerful way to learn JavaScript arrays. What you do is pick a couple options from drop-down lists to find the right array method you need for a project.

I still find arrays challenging and yet learning how to work with them in JavaScript is so important. If you’re still figuring this stuff out, definitely take a look at Array Explorer, bookmark it, and use it.

Sarah even made the code for Array Explorer available on GitHub so you can see how she put it together too.

An awesome thread about developers’ careers

Stephanie Hurlburt asked for stories from developers about their career paths on Twitter, and it quickly became one of the best threads I’ve read in a while. As you can imagine, I have a particular interest in stories about other developers’ careers given my journey this year. This thread didn’t disappoint.

I started reading the thread when I woke up this morning and, boy, what a great way to start a day.

Inspiring developers make Twitter worthwhile

Twitter has become a complicated digital space, to say the least. My “Inspiring developers” Twitter list is one of the highlights of my Twitter experience, and the developers on that list make Twitter worthwhile for me, despite all the cruft we see there.

One of the themes that Twitter has helped highlight is how women developers are routinely marginalised, dismissed, devalued. I decided to seek out inspiring women developers and follow them because I was interested in their perspectives on development, life, and other issues.

I’m glad I did. Sure, there are some men on that list (there are plenty of male developers who I admire too) but I wanted to be exposed to different voices.

I am continually inspired by the developers I add to my list, and there are times when I’m tempted to unfollow virtually everyone else and just focus on this growing group of smart, thoughtful, and innovative professionals. See for yourself:

I have learned so much from virtually every person on this list. The fact that this list began as an effort to focus on women developers has become secondary to how much I appreciate being able to subscribe to their shared thoughts.

By the way, if there are developers who aren’t on my list and who inspire you, let me know in the comments or on Twitter?

Photo credit: WOCinTech Chat, licensed CC BY SA 2.0