The Math Standard Library in Python

Time to wrap up this first week of learning python on my own, today I think I will be taking a look at one of the many standard libraries to work with in python starting with the math library.

In javaScript there is the built in Math object that contains all kinds of useful properties and methods that help with working out all kinds of Math expressions. So when it comes to Python there should be another such Object, or built in module at least to work with and it would seem that there is. However things are a little broken up with some things, for example when it comes to absolute value there is a built in absolute value method in python itself, and there is another such method in the math module. Also when it comes to generating random numbers there is no such method to be found in the standard math module, instead there is yet another module called random that contains such a method. So depending on what I need to do, it would be best to look at what there is to work with on built in functions first. Then if I might look at the math module, but even then there is more than one math module.

Anyway in todays post I am going to be looking at some of the methods that there are to work with when it comes to the standard built in math library in python. I will also be taking a look at some other features of python itself, and other libraries to work with in order to truly get up and running with some math in python.

1 - The Math Standard Library in Python

So this is mainly a post on the Standard Math Library in python, so of course I will be staring off with a few examples that make use of this Library. However I will not be covering every little method and property in this section for several reasons. One reason would be that there is all ready comprehensive documentation on the math library at the python.org website that will go over everything. The other reason why is that there are only a few methods that are truly needed here as there are other basic math methods that are some of the python built in functions. Also the main math module does not have everything outside of the built in functions.

So in this section I will be going over some of the methods that I will likely be using in real projects now and then

1.1 - Math.e

The math.e property of the math library stores Euler’s number. This is a property that I find myself using now and then when it comes to working out some expressions that have to do with logarithms, as this math.e constant is the base of the natural logarithm.

import math
 
print(math.e)         # 2.718281828459045
 
n = math.pow(2, 52)
e = math.pow( 1 + 1 / n, n)
print(e)              # 2.718281828459045
print( math.e == e )  # true

1.2 - Math.log

Another useful method that I might use now and then from the main library is the math.log method. This is a useful method for working out any kind of expression that works with logarithms. This math.log method can take two arguments the first of which is the number that I want a logarithm for and the second is a base argument. The default base for the math.log method is math.e, or Euler’s constant if you prefer.

import math
 
a = math.log(2)
b = math.log(2, math.e)
 
print(a)      # 0.6931471805599453
print(a == b) # True

2 - Python Built in Math functions

So now that I have covered some basic examples of the Math library maybe now I should review some of the built in functions in python. Not all of them of course, but certainly all the ones that have to do with Math. In the math library there is for example a method that can eb used to get the absolute value of a number, and also another method to get a power. However when it comes to just working with the built in methods for python alone there is an absolute value method, and power method also. There are also a great deal of other basic math methods in the collection of python built in functions, so in this section I will be going over these.

1.1 - The abs built in function

There is an absolute value method in the math library, but why bother with that when there is an absolute value method that can just be used in python itself.

print( abs(-5) ) # 5

1.2 - hex

If I need to convert an integer value to a hex value then there is the hex function.

print( hex(16) )  # 0x10
print( hex(32) )  # 0x20
print( hex(48) )  # 0x30
print( hex(64) )  # 0x40
 
print( hex(255) ) # 0xff

1.3 - min and max

If I want to get the lowest or highest number in a list of numbers there is the max and min functions.

n=[1, -8, 32, 0, 1024, -3]
 
print( max(n) ) # 1024
print( min(n) ) # -8

1.4 - oct

There is the oct function that is just like hex only it will return a number as an octal rather than hex.

print( oct(8) )  # 0o10
print( oct(16) ) # 0o20
print( oct(24) ) # 0o30
print( oct(32) ) # 0o40
print( oct(40) ) # 0o50
 
print( oct(64) ) # 0o100

1.5 - pow

There is of course a math.pow function in the math library, however there is also just using the pow built in function.

n = pow(2,10)
 
print(n) # 1024

1.6 - round

There might be more than one round function in the math library, such as floor and ceil. However if I just need a basic round function then there is the round function in python by itself.

pi=3.14159
print( round(pi) ) # 3
print( round(pi, 3) ) # 3.142
 
pi = pi * -1
print( round(pi) ) # -3
print( round(pi, 3) ) # -3.142

1.7 - sum

When it comes to built in functions in python there is also the sum function.

nums=[1,2,3,4,5,5,10]
 
print( sum(nums) ) # 30

3 - Other Math modules in python

So I have went over some of the basics of the math library, and also some of the python built in functions that have to do with math. However there is still a great deal missing when it comes to even just basic math methods. For example coming from a javaScript background there is the Math.random method that will return a random number between 0 and 1. No such method is there as one of the built in functions, and in addition there is not a random number method in the standard math library also. There is however a random method in yet another standard library called random. So with that said in this section I will be going over some examples that have to do with other standard library that have to do with math that will help to complete the set of basic functions to work with when it comes to creating some expressions in python.

3.1 - The random method of the random library

The random library is where I will find the equivalent of the Math.random function in the Math object of javaScript.

import random
 
print( random.random()) # random floating point number in the range [0.0, 1.0)

3.2 - The randinit method of the random library

There is also a random function in the random module that will give me a random integer between and including two numbers given as a range.

import random
print( random.randint(0, 1)) # random number 0-1
print( random.randint(1, 6)) # random number 1-6

4 - Conclusion

Well that is it for now when it comes to the math standard library in python, along with some additional stuff that has to do with other related modules and features of python. I think the next step from here is to just start working out some real examples that have to do with math in order to really get the hang of how to work with the math library. For example in another project that I have been working on lately I have been working out a new experience point system that makes use of methods that use Math.log.