As nice as it is to write a for-my-eyes-only script to solve a specific problem on my Mac, it is satisfying in an entirely new way to write code on a mobile device. It just feels less like "programming" and more like making a better pocket knife.

A mundane problem I wanted to solve:

I love budgeting, but not as much as I love food. It's always been a struggle for me to manage what I'm spending eating out over the course of a month—especially since what my family and I spend at restaurants tends to vary a lot in size and frequency.

It's easy to set a food budget at the beginning of the month, and it's easy to see whether we came in under or over that budget at the end of the month, but it's a lot harder to ascertain whether or not I'm on track as the days of the month tick by.

The pocket knife solution:

I wrote a simple Python script in Pythonista that takes a monthly dollar figure—my remaining food budget for the month—and averages it over the remaining days in the current month:


import datetime, calendar
import sys
import console

budget = float(sys.argv[1])

d = datetime.datetime.today().day
m = datetime.datetime.today().month
y = datetime.datetime.today().year
last = calendar.monthrange(y,m)[1]

remaining_per_day = budget / (last - d)
message = 'You have $' + str(round(remaining_per_day,2)) + ' remaining per day for the next ' + str(last - d) + ' days.'

console.clear()
print message

The Python script itself is fairly unremarkable, but what impressed the hell out of me is that I was able to write it entirely on my iPhone, then slap a "GUI" on it using Launch Center Pro.

I don't even have to open Pythonista to use it. I just tap a Launch Center Pro action, enter a dollar figure, and Launch Center Pro sends it to Pythonista, which runs the script and puts an answer in the console.

  <img src="/img/img.gif" alt=""/>

This little workflow takes advantage of Pythonista's ability to accept standard input via its URL scheme and Launch Center Pro's ability to send a URL that consists partly of numeric keypad input.

   [caption id="" align="alignnone" width="400.0"]<img src="/img/img.png" alt="In LCP's action settings, enter Pythonista's URL scheme in the URL field along with [prompt-num], which is LCP's variable for keypad input. The name of the Python script in this example is Budget.py."/> In LCP's action settings, enter Pythonista's URL scheme in the URL field along with [prompt-num], which is LCP's variable for keypad input. The name of the Python script in this example is Budget.py.[/caption]

This was a mundane problem, but the solution feels remarkable.

To me, Pythonista is a very important app because it feels like an obvious step toward a future where more software creation will happen on devices that we don't think of as "computers" in the conventional sense.

Maybe I'm overblowing all this, but I just think it's amazing that I can write a piece of code on a mobile device, then snap a few blocks together to essentially create a custom app. I can't help but think the future of programming won't feel like "programming"—much like using an iPhone doesn't feel like "computing."

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