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- [Instructor] As we've discussed,

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there are quite a number of libraries

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available to you as part of

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the Python standard library.

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In this video, I just
wanna take a brief look

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at the math module within
the Python standard library

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which contains many common
mathematical functions.

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In order to use those functions,

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you will need to import the math library.

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You may recall that I've demonstrated

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some tab completion capabilities,

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so if you want to see
what's in the math library,

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you can now type math dot and hit Tab,

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and now you can see all of
these different functions

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and a couple of variables;

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e, pi, nan, tau.

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Each of these are technically constants

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that you can use in your code,

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but in Python, we don't actually have

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true constant data,

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which means you could accidentally modify

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the variables that are pre-defined

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in the math module

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if you assign a new value to them.

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So you do wanna be careful

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not to accidentally
overwrite those variables

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once you import them into your code.

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As you can see here, there's a whole bunch

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of functions available for your use.

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Let's say you don't know

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how to use a particular function

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and you wanna learn more about it.

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You can type the name of the function

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and a question mark, and once again,

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it will give you some documentation

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about that particular function.

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For instance, if I wanna go ahead

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and calculate the square root of a value,

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let's say we wanna do
the square root of 900,

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you can see quickly that the
square root of 900 is 30.

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Similarly, let's say
we wanted to calculate

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the absolute value of a negative number.

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We could use FABS,

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which is floating point absolute value,

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and you can see that it gives you back

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the positive result of
calling that function.

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Again, if you have any use

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for basic mathematical functionality,

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you'll definitely want to take a look

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at the math library.

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Similarly, in the online documentation

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that I've shown you a couple of times now

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at python.org, you will
definitely want to go back

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once again and take a
look at that master list

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of all the different
modules that are built-in

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to the Python standard library for you

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so that you can get a
sense of the categories

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of functionality that are available.

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Eventually, you'll
probably want to dive into

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a number of those libraries

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to see what pre-existing
capabilities they give you.

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In Python, they take

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the everything but the
kitchen sink approach

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where they include as much as possible

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so that you can focus on the logic

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of what you need to get done

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as opposed to the low-level details

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of how to perform everyday tasks

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that lots of Python
programmers have performed

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in the past.

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That's just with the
Python standard library.

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That doesn't include the
thousands of other libraries

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that are available to you,

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most of which are open source.

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You can access many of them
on sites like github.com.