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How to represent an infinite number in Python?

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How to represent an infinite number in Python?
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Infinity is an undefined number which can be negative and positive. A number is used as infinity sometimes, the sum of two numeric may be numeric but can be a different pattern, it may be negative or positive value.

It is used to compare solution in algorithms for best solution. Generally, a value set at the initial start may be positive or negative infinity, we have to take care that no input value is bigger or smaller.

Infinity and Nan are two kinds of exceptional floating values in Python.

In comparison, positive infinity is always bigger than every natural number.

(i.e.  0,1,2,.......... +∞. Positive integer and  +infinity.)

In comparison, negative infinity is smaller than negative number.

(i.e. ∞-.......-2,-1,0, 1,.2,3.........  – negative infinity and -integer.)

In python, we cannot represent infinity or we can say that there is no way to show the infinity as an integer. But we can use float (inf) as an integer.

How to represent positive and negative infinity in Python:

ptive_inf = float(“inf”)  // for Positive infinity

ntive_inf = float(“-inf”) // for Negative infinity

Infinity in Python 3.5

import math

test = math.inf

If we compare

ptive_inf > 1
ptive_inf > 1000000

It always true.

Python Infinity and NaN (“not a number”)

As we know that inf is infinity and is the undefined biggest number among positive numbers. When we try to subtract any number out of it then we get a “Not a number” (NaN). Even though infinity is the biggest integer but undefined, when something is undefined how can you subtract something from it, therefore, an error is NaN.

NaN can be represented in Python using 3 basic ways:

n= float ('-inf'), for storing a negative infinite number
p= float ('inf'), for storing a positive infinity number

In Python 3 and higher, the NaN number is represented using the math.nan after importing the math module.

For example, nan=math.nan
This number can be evaluated using math.isnan(nan), where the nan is the argument passed to check whether it is NaN or not.

Example

ptive_inf = float (‘inf’)             #positive infinity
ntive_inf = float(‘-inf’)            #negative infinity
nann = float(‘nan)                  #Not a Number (NaN)

math.inf in Python

math.inf is a module in python, when we are talking about the infinity, it is assigned to a float variable with the help of inf as a float argument. This ‘inf’ constant is available with a math module. When we are dealing with the infinity we import math module.


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