Noah Gift - Minimal Python

Noah Gift

Another common failure point in learning Python is that the installation may be tricky. One of the ways around this is to use a hosted environment to learn Python. An excellent environment for learning is Google Colab

The examples in this chapter can run from this Google Colab notebook.

The first thing to be aware of in starting to program is to learn about executing statements. You can run commands by typing them in. Here is a print function.

The output is:

The big takeaway is your already a programmer. If you can type commands in, you solved 80% of the challenge of writing code. Even further, you can program like this for the REST OF YOUR LIFE! If you are a data scientist, you may never type more than a statement.

Ok, now that you passed that hurdle and youre a programmer, lets step it up a bit and use Python as a calculator. Here is a simple 1+1 example.

The output is

Here is your first challenge of the book. A challenge ensures you have grasped each concept.

Challenge: Do another calculation using addition or subtraction

Ok, so what did you try? Did it work? If not, no big deal. Mistakes are a necessary part of being a programmer. The sooner you accept that mistakes are a great thing, the quicker you learn.

In regular life, you dont normally encounter things that are in a continuous state of brokenness. In programming, everything is in a state of brokenness. The secret to getting good very quick is to accept this and make it create a smile on your face. Mistakes mean you are learning quickly. The more mistakes you make, the more you learn.

Procedural statements are literal statements that can be issued one line at a time. Below are the types of procedural statements. These statements can run in:
* Jupyter Notebook
* IPython shell
* Python interpreter
* Python scripts

You can also chain multiple procedural statements together by executing them one by one. In writing a script or doing data science this is very common. You can think of it like to-do list you write first thing in the morning.

Python also works identical to the way a desktop calculator works. If you type in numbers and add them together you get a sum. The only difference in this example is that the numbers are assigned variables.

Adding Phrases

Python can also add together strings by using the + operator. This is similar to putting words on post-its then assembling them into funny phrases. If you have word magnets on your fridge and mix them together to create a sentence than you are essentially doing the same thing.

Complex statements

More complex statements use loops. This is a for loop. The main reason for using a loop is to do something to a group of items. In this example there are several items in the three_type_of_energy list.

What is the analogy for the real world? Imagine a shopping list. You walk into a store and loop to each aisle of the store and pick up each item in the list. This is a for loop in the real world.

There are other expressions that are helpful in programming. Here are some examples.

In the real-world we use the concept of assert often. You may ask which gas station has the lowest prices from a friend. To double check you may go to their website and assert whether your friend is correct. You can do the same thing in Python. This example asks Python to assert whether the variable carbohydrate is equal to 9.

Python throws an AssertionError which allows a programmer to later catch this exception and do somethign with it. Perhaps this could be part of a test suite. Many popular test frameworks use assert to test statements or modules.

Notice this statement works.

Another handy tool is pass. It can be used to fill in a statement and do nothing. The following statement shows that