How do you get to base 10 in python?

Description

The log10() method returns base-10 logarithm of x for x > 0.

Syntax

Following is the syntax for log10() method −

import math

math.log10( x )

Note − This function is not accessible directly, so we need to import the math module and then we need to call this function using the math static object.

Parameters

x − This is a numeric expression.

Return Value

This method returns the base-10 logarithm of x for x > 0.

Example

The following example shows the usage of the log10() method.

#!/usr/bin/python3
import math   # This will import math module

print ("math.log10(100.12) : ", math.log10(100.12))
print ("math.log10(100.72) : ", math.log10(100.72))
print ("math.log10(119) : ", math.log10(119))
print ("math.log10(math.pi) : ", math.log10(math.pi))

Output

When we run the above program, it produces the following result −

math.log10(100.12) :  2.0005208409361854
math.log10(100.72) :  2.003115717099806
math.log10(119) :  2.0755469613925306
math.log10(math.pi) :  0.49714987269413385

python_numbers.htm

Description

Python number method log10() returns base-10 logarithm of x for x > 0.

Syntax

Following is the syntax for log10() method −

import math

math.log10( x )

Note − This function is not accessible directly, so we need to import math module and then we need to call this function using math static object.

Parameters

• x − This is a numeric expression.

Return Value

This method returns base-10 logarithm of x for x > 0.

Example

The following example shows the usage of log10() method.

#!/usr/bin/python
import math   # This will import math module

print "math.log10(100.12) : ", math.log10(100.12)
print "math.log10(100.72) : ", math.log10(100.72)
print "math.log10(119L) : ", math.log10(119L)
print "math.log10(math.pi) : ", math.log10(math.pi)

When we run above program, it produces following result −

math.log10(100.12) :  2.00052084094
math.log10(100.72) :  2.0031157171
math.log10(119L) :  2.07554696139
math.log10(math.pi) :  0.497149872694

python_numbers.htm

Python math.log10() function is a library method of the math module, and it is used to get the base-2 logarithm of the number; it accepts a number and returns the base-10 logarithm of the given number.

Python log10() is a built-in math library function used to get the logarithm of any given number with base 10. To use log10() function in Python, import the math library to use this function. The log10() method returns the base-10 logarithm of x for x > 0.

Syntax

math.log10(num)

The log10() function takes two arguments:

num -> whose log we want to find with base 10.

Return Value

Python log10() function returns the logarithm of base 10, particularly given number.

But this function throws a ValueError exception if any value is passed as an argument.

Programming Example

See the following code.

# Importing math library
import math

# initializing values

# positive value
num = 10
print("Logarithm with base 10 of the value ", num, " is: ", math.log10(num))

# Negative number
num = -10
print("Logarithm with base 10 of the value ", num, " is: ", math.log10(num))

Output

Logarithm with base 10 of the value  10  is:  1.0
Traceback (most recent call last):
  File "1log10.py", line 12, in 
	print("Logarithm with base 10 of the value ",num," is: ",math.log10(num))
ValueError: math domain error

In this program, we initialized the value, then calculated the logarithm of the number with base 10. In the next line, we wanted to calculate the logarithm of a negative number, but as per rule, the program threw an exception of ValueError.

Program 2

See the following program.

# app.py

# Importing math library
import math

# taking input from user values

# positive value
num = int(input("Enter a num to find log10(num): "))
print("Logarithm with base 10 of the value ", num, " is: ", math.log10(num))

Output

Enter a num to find log10(num): 15
Logarithm with base 10 of the value  15  is:  1.1760912590556813

In this program, we have taken input from the user and calculated the logarithm of base 10.

Python log10() with list and tuple

Let’s apply the log10() function to the list and tuple, and see the output. See the following code.

import math

Tup = (1, 2, 11, -4, 5)  # Tuple Declaration
Lis = [-1, 2, -11.21, -4, 5]  # List Declaration

print('The log10() value of Positive Number = %.2f' % math.log10(1))
print('The log10() value of Positive Decimal = %.2f' % math.log10(2.5))

print('The log10() value of Tuple Item = %.2f' % math.log10(Tup[2]))
print('The log10() value of List Item = %.2f' % math.log10(Lis[4]))

print('The log10() value of Multiple Number = %.2f' % math.log10(2 + 7 - 5))
print('The log10() value of String Number = ', math.log10('Locke and Key'))

Output

python3 app.py
The log10() value of Positive Number = 0.00
The log10() value of Positive Decimal = 0.40
The log10() value of Tuple Item = 1.04
The log10() value of List Item = 0.70
The log10() value of Multiple Number = 0.60
Traceback (most recent call last):
  File "app.py", line 13, in 
    print('The log10() value of String Number = ', math.log10('Locke and Key'))
TypeError: must be real number, not str

If you pass a string, it gives the TypeError.

Conclusion

Python log10() function calculates the logarithmic value of the given number of base 10. First, we find the base 10 logarithmic value of different data types and display the output.

See also

Python log(2)

Python log(x, base)

Python log1p(x)

Python exp()

Python trunc()

How do you do Base 10 in python?

How do I use log10?

How do you find base

How do you take the log of a number in Python?