Introduction to Python modules

Introduction to Python modules

1. Module

   • Definition
     • Separately saved unit whose functionality can be reused at will

2. Purpose of modules.

   • Code reusability.

3. Importing Modules

   • Using the import statement.
     • Syntax: import module_name.
     • Example: import math.
   • Importing specific functions or classes.
     • Syntax: from module_name import function_name.
     • Example: from math import sqrt.

4. Commonly Used Modules

   • math module
     • Purpose of math modules
       • Provide mathematical functions
     • Contants
       • pi
         • mathematical constant
         • used in geometry
         • syntax: math.pi
       • e
         • The math. e constant returns the Eular's number: 2.718281828459045
     • Functions
       • ceil()
         • Rounds a number up to the nearest integer
           • print(math.ceil(4.2)) Output: 5
           • print(math.ceil(-4.2)) Output: -4
       • sqrt()
         • Function to calculate the square root Part of the math module Returns a float
           • Access using 'math.sqrt()'
       • exp()
         • Returns e raised to the power of a given number
           • syntax: math.exp(x)
       • fabs()
         • Function to compute the absolute value
           • Returns the non-negative value
           • Example
             • math.fabs(-5) returns 5.0
             • fabs(3.2) returns 3.2
       • floor()
         • Rounds down to nearest integer
         • Example
           • floor(3.7) returns 3
           • floor(-3.7) returns -4
       • pow()
         • Computes power of a number
         • math.pow(2, 3) returns 8
       • sin()
         • Returns sine of an angle
   • random module
     • random()
       • Function to generate random numbers
         • random.random()
     • randint()
       • Function to generate random integers
         • Example: random.randint(1, 10)
     • randrange()
       • A function to generate random numbers
         • Syntax: randrange(start, stop[, step])
           • Example: result = randrange(0, 20, 5)
             • Generates 0, 5, 10, 15 (exclusive of 20).
   • statistics module
     • mean()
       • Calculates the average of numerical values
         • statistics.mean(data)
     • mode()
       • Most frequently occurring value
         • Example
           • data = [1, 2, 2, 3]
             • `statistics.mode(data)` returns `2`
     • median()
       • Median is the middle value
         • statistics.median(data)