Module import Syntax Python Tutorial

Now that we've used a module, statistics, it would be a good time to explain some import syntax practices. As with many things in programming, there are many ways to import modules, but there are certainly some best practices.

So first, when you import a module, you are basically loading that module into memory. Think of a module like a script. Many if not most modules are just a single python script. So, when you go to import it, you use the file name. This can help keep code clean and easy to read. Many python developers just program everything in 1 script. Other developers, say from a language like java are going to be very used to doing lots of imports with a file for each type of job that's happening. Just like there are many ways to import, there are many more ways to program.

So let's talk about basic importing:

import statistics

Above, we have referenced the statistics module and loaded it into memory under the statistics object. This will allow us to reference any of the functions within the statistics module. To do so, we will need to mention statistics, followed by a period, then the function name. A simple exhibition of the mean function from statistics could look like this:

import statistics

example_list = [5,2,5,6,1,2,6,7,2,6,3,5,5]

print(statistics.mean(example_list))

The generated output from this will be the mean, or average, of the list.

That is the simplest way to import and use modules, but there are many other methods. In the video, we cover each one specifically, but here are a bunch of examples:

Sometimes, however, you will see people use the "as" statement in their imports. This will allow you to basically rename the module to whatever you want. People generally do this to shorten the name of the module. Matplotlib.pyplot is often imported as plt and numpy is often imported as np, for example.

import statistics as s

print(s.mean(example_list))

Above, we've imported statistics as the letter 's.' This means whenever we wish to reference the statistics module, we just need to type 's' instead of statistics.

What if you don't even want to type that S though? Well there's an app for that!

You can just import each function within the module you plan to use:

from statistics import mean
# so here, we've imported the mean function only.
print(mean(example_list))

# and again we can do as
from statistics import mean as m
print(m(example_list))

Above, you can see that we no longer had to type any reference to the statistics module, then you saw that we could even import the functions "as" something else.

What about more functions?

from statistics import mean, median
# here we imported 2 functions.
print(median(example_list))

What if we want to use the as as well?

from statistics import mean as m, median as d

print(m(example_list))
print(d(example_list))

What if we want to just import everything from statistics like we did initially, but we don't want to type the statistics because we have fat fingers and this will just slow us down?.

from statistics import *

print(mean(example_list))

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The next tutorial: Making your own Modules Python Tutorial