# Python math.log10() Method

The Python programming language offers a library, `math`, that contains implementation for various mathematical operations such as trigonometric functions and logarithmic functions.

Logarithm refers to the inverse function of exponentiation. Simply put, the logarithm of a number `a` is the exponent or number (`x`) to which another number, the base `b`, should be raised to make that number `a`.

In this article, we will discuss a method, `log10()`, available in the `math` module that computes the logarithm of a number with base `10`.

## Syntax

``````math.log10(x)
``````

### Parameters

Type Description
`x` Float A non-negative integer and non-zero value.

### Return

The `log10()` method returns the logarithm to the base of `10` for a number. It is equivalent to `math.log(x, 10)` and, in some cases, more accurate than it.

## Example 1: Base-10 Logarithm of a Number

``````import math

print(math.log10(0.000001))
print(math.log10(1))
print(math.log10(0.341))
print(math.log10(99999))
print(math.log10(2352.579))
``````

Output:

``````-6.0
0.0
-0.4672456210075022
4.999995657033466
3.3715442160261846
``````

The Python code above computes the base-10 logarithm value for `0.000001`, `1`, `0.341`, `99999`, and `2352.579`. Note that these values are non-negative and non-zero.

For inputs in the range `(0, 1)`, the base-10 logarithm returns negative results. On the flip side, the range `[1, ∞)` yields positive results.

## Example 2: If Input Is Not a Number

``````import math

print(math.log10("this is a string"))
``````

Output:

``````Traceback (most recent call last):
File "main.py", line 3, in <module>
print(math.log10("this is a string"))
TypeError: must be real number, not str
``````

The Python code above takes a string as an input. Since the `log10()` method expects a numeric value such as an integer or a float, it raises a `TypeError` exception.

## Example 3: If Input Less Than or Equal to `0`

``````import math

print(math.log10(0))
``````

Output:

``````Traceback (most recent call last):
File "main.py", line 3, in <module>
print(math.log10(0))
ValueError: math domain error
``````

The Python code above takes `0` as input, and since `0` is out of the `log10()` method’s domain, it raises a `ValueError` exception.

``````import math

print(math.log10(-99.09))
``````

Output:

``````Traceback (most recent call last):
File "main.py", line 3, in <module>
print(math.log10(-99.09))
ValueError: math domain error
``````

The Python code above takes `-99.09` as input which is less than `0`. Such values are invalid for the `log10()` method because they lie outside its domain.

Hence, it raises a `ValueError` exception.

## Example 4: If Input Is Infinity

``````import math

print(math.log10(math.inf))
``````

Output:

``````inf
``````

The logarithm of infinity to base `10` is infinity.

## Example 5: If Input Is `NaN`

``````import math

print(math.log10(math.nan))
``````

Output:

``````nan
``````

Vaibhav is an artificial intelligence and cloud computing stan. He likes to build end-to-end full-stack web and mobile applications. Besides computer science and technology, he loves playing cricket and badminton, going on bike rides, and doodling.