Introduction to Python

I have been wanting to learn python for some time, mostly because a lot of my favority open source projects use it and seek people with that expertise, so finally here I am taking my first steps with python.

There are two things that really catch my eye about python:

– Doesn’t use brackets to group statement

– Doesn’t use semicolons to end lines

These two semantic rules of python freak me out a little, maybe because I am so used to brackets and semicolons that I can’t imagine a programming language that doesn’t use them. But they claim this makes programming easier, so I hope they are right.

Installation

There is not really much I can say about installation because when I checked I already had the python interpreter installed.

I imagine that if you don’t have it doing this in ubuntu would be enough:

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sudo apt-get python

You can verify that you have it installed by typing python in a terminal. You will get a »> prompt, use Ctrl+D to quit the prompt.

An easy example

The first examples seen in python’s documentation are run in interactive mode (from the »> prompt), but since I don’t think I will be using that mode a lot in real life, I will write my example in a file called example.py.

I will use the same example used on python’s documentation, the fibonacci series (if you don’t know it go check wikipedia, it is a really simple algorithm).

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a = 0
b = 1
x = 0
while b < 1000:
    # Automatically adds \n character after printing the value of the variable
    print b
    x = b
    b = a + b
    a = x

Python’s documentation does the same thing in a more efficient but also more confusing (at least for a beginner) way:

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# This weird little piece of code is the same as saying
# a = 0
# b = 1
# it takes all variables at the left of the equal sign and assigns
# all values at the right of the equal sign in their corresponding
# positions
a, b = 0, 1
while b < 10:
    print b
    # This next piece of code is even weirder than the last assignation.
    # With a little python magic they avoid the use of a helper variable.
    # The python interpreter first solves a+b, then assigns b to a and
    # then assigns the value of the operation it made (a+b before modifying a)
    # to b
    a, b = b, a+b

Now we have the code in our example.dev file we can execute it just by typing in a terminal:

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python example.py

Conclusions

I didn’t expect python to be so different from other programming languages I have used in the past, but I really got a big surprise. I have heard a lot of good things about python, so I don’t plan to be give up just because the syntax is a little different. Overall the experience has been eye opening and I can’t wait to learn more about the language.