Maths Functions - Python
Standard arithmetic can be performed without any additional code (ie -+/*%). However you can extend this by importing some of the default modules installed with python. These are math, random, statistic, decimal and fraction:
Contents
Math Functions
A range of mathematical functions is available from math module of the standard library:
import math #import the math module
print math.sin(10) # sine
print math.cos(10) # cosine
print math.tan(10) # tangent
print math.asin(10) # arc sine
print math.acos(10) # arc cosine
print math.atan(10) # arc tangent
print math.sinh(10) # hyperbolic sine
print math.cosh(10) # hyperbolic cosine
print math.tanh(10) # hyperbolic tangent
print math.pow(2, 4) # 2 raised to 4
print math.exp(4) # e ^ 4
print math.sqrt(10) # square root
print math.pow(5, 1/3.0) # cubic root of 5
print math.log(3) # ln; natural logarithm
print math.log(100, 10) # base 10
print math.ceil(2.3) # ceiling
print math.floor(2.7) # floor
print math.pi
print math.e
Random Functions
Pseudo-random generators are available from the random module:
import random #import the random module
print random.random() # Uniformly distributed random float >= 0.0 and < 1.0.
print random.random()*10 # Uniformly distributed random float >= 0.0 and < 10.0
print random.randint(0,9) # Uniformly distributed random int >= 0 and <=9
li=[1, 2, 3]; random.shuffle(li); print li # Randomly shuffled list
Decimal Functions
The decimal module enables decimal floating point arithmethic.
import decimal #import the decimal module
plainFloat = 1/3.0
print plainFloat # 0.3333333333333333
decFloat = decimal.Decimal("0.33333333333333333333333333333333333333")
print decFloat # Decimal('0.33333333333333333333333333333333333333')
decFloat2 = decimal.Decimal(plainFloat)
print decFloat2 # Decimal('0.333333333333333314829616256247390992939472198486328125')
Fraction Functions
Compared to floating point numbers representing fractions, Fraction fractions do not lose precision.
from fractions import Fraction #import the fraction module
oneThird = Fraction(1, 3)
floatOneThird = 1/3.0
print Fraction(0.25) # 1/4
print Fraction(floatOneThird) # 6004799503160661/18014398509481984
print Fraction(1, 3) * Fraction(2, 5) # 2/15
Statistical Functions
Python also has built in statistical fucntions:
<syntaxhighlightlang="python"> import statistics as stats #import the statistics module print stats.mean([1, 2, 3, 100]) # 26.5 print stats.median([1, 2, 3, 100]) # 2.5 print stats.mode([1, 1, 2, 3]) # 1 print stats.pstdev([1, 1, 2, 3]) # 0.82915...; population standard deviation print stats.pvariance([1, 1, 2, 3]) # 0.6875; population variance </syntaxhighlight>