Python Program for log() Function

In the previous article, we have discussed Python Program for expm1() Function
log() Function in Python:

The math.log() method returns the natural logarithm of a number or the base logarithm of a number.

Syntax:

math.log(x, base)

Parameters:

x: This is required. It is a number. It Specifies the value for which the logarithm should be calculated. If the value is 0 or a negative number, a ValueError is returned. If the value is not a number, a TypeError is returned.

base: This is optional. The logarithmic base that should be used. ‘e’ is the default.

Return Value:

Returns a float value corresponding to the natural logarithm of a number or the logarithm of a number to base.

The log function returns the output if the number argument is positive.
If the number is negative or zero, the log function throws a ValueError.
If it is not a number, the log function throws a TypeError.

Examples:

Example1:

Input:

Given first number = 1
Given second number = 6

Output:

The result after applying log() function on above given first number 1  =  0.0
The result after applying log() function on above given second number 6  =  1.791759469228055

Example2:

Input:

Given first number = 7
Given second number = 9

Output:

The result after applying log() function on above given first number 7  =  1.9459101490553132
The result after applying log() function on above given second number 9  =  2.1972245773362196

Method #1: Using Built-in Functions (Static Input)

Approach:

Import math module using the import keyword.
Give the list as static input and store it in a variable.
Give the first number as static input and store it in another variable.
Apply math.log() function to the given first number to get the natural logarithm or the base logarithm of a given number.
Store it in another variable.
Print the above result.
Similarly, do the same for the other number.
Apply the math.log() function to the given list element and print it.
The Exit of Program.

Below is the implementation:

# Import math module using the import keyword.
import math
# Give the list as static input and store it in a variable.
gvn_lst = [10, 5, 20, 25, 12]
# Give the first number as static input and store it in another variable.
gvn_numb1 = 1
# Apply math.log() function to the given first number to get the natural logarithm
# or the base logarithm of a given number.
# Store it in another variable.
fnl_rslt = math.log(gvn_numb1)
print("The result after applying log() function on above given first number",
      gvn_numb1, " = ", fnl_rslt)
# similarly do the same for the other number.
gvn_numb2 = 6
print("The result after applying log() function on above given second number",
      gvn_numb2, " = ", math.log(gvn_numb2))
# Apply math.log() function to the given list element and print it.
print(
    "The result after applying log() function on given list element gvnlst[1] = ", math.log(gvn_lst[1]))

Output:

The result after applying log() function on above given first number 1  =  0.0
The result after applying log() function on above given second number 6  =  1.791759469228055
The result after applying log() function on given list element gvnlst[1] =  1.6094379124341003

Method #2: Using Built-in Functions (User Input)

Approach:

Import math module using the import keyword.
Give the list as user input using list(),map(),input(),and split() functions.
Store it in a variable.
Give the first number as user input using the float(input()) function and store it in a variable.
Apply math.log() function to the given first number to get the natural logarithm or the base logarithm of a given number.
Store it in another variable.
Print the above result.
Similarly, do the same for the other number.
Apply the math.log() function to the given list element and print it.
The Exit of Program.

Below is the implementation:

# Import math module using the import keyword.
import math
# Give the list as user input using list(),map(),input(),and split() functions.
# Store it in a variable.
gvn_lst = list(map(float, input(
    'Enter some random List Elements separated by spaces = ').split()))
# Give the first number as user input using the float(input()) function
# and store it in a variable.
gvn_numb1 = float(input("Enter some random number = "))
# Apply math.log() function to the given first number to get the natural logarithm
# or the base logarithm of a given number.
# Store it in another variable.
fnl_rslt = math.log(gvn_numb1)
print("The result after applying log() function on above given first number",
      gvn_numb1, " = ", fnl_rslt)
# similarly do the same for the other number.
gvn_numb2 = float(input("Enter some random number = "))
print("The result after applying log() function on above given second number",
      gvn_numb2, " = ", math.log(gvn_numb2))
# Apply math.log() function to the given list element and print it.
print(
    "The result after applying log() function on given list element gvnlst[2] = ", math.log(gvn_lst[2]))

Output:

Enter some random List Elements separated by spaces = 4 5 3 1 2
Enter some random number = 7
The result after applying log() function on above given first number 7.0 = 1.9459101490553132
Enter some random number = 9
The result after applying log() function on above given second number 9.0 = 2.1972245773362196
The result after applying log() function on given list element gvnlst[2] = 1.0986122886681098

Know all about Mathematical Functions in Python by going through our Python Mathematical Methods Examples well explained step by step.