Learn Python variables with this beginner-friendly guide. Understand variable naming rules, assignments, and operations with examples and exercises. Perfect for students and professionals starting their Python journey.
pip
.You can import a module or specific functions from it using the import
keyword.
import math
print(math.sqrt(16)) # Output: 4.0
from math import sqrt
print(sqrt(16)) # Output: 4.0
as
:
import numpy as np
print(np.array([1, 2, 3]))
Python comes with many useful built-in modules. Some commonly used ones include:
math
: Provides mathematical functions like sqrt()
, pow()
, and constants like pi
.datetime
: Useful for handling date and time operations.random
: For generating random numbers.os
: For interacting with the operating system (e.g., file manipulation).Example with random
:
import random
print(random.randint(1, 10)) # Random integer between 1 and 10
To install third-party libraries, you can use pip
. For example, to install the popular requests
library:
pip install requests
Once installed, you can import it and use it in your code:
import requests
response = requests.get('https://www.example.com')
print(response.text)
You can organize your code into modules by saving your functions or classes in separate Python files. For example, if you have a file mymodule.py
:
# mymodule.py
def greet(name):
return f"Hello, {name}!"
You can import and use the module like this:
import mymodule
print(mymodule.greet("Alice"))
math
modulemath
module to calculate the area of a circle. The formula is Area = π * r²
, where r
is the radius.math
module.calculate_area(radius)
that returns the area of the circle.random
modulerandom
module.randint()
function to simulate the die rolls.mymodule.py
.is_prime(n)
that returns True
if the number is prime and False
otherwise.is_prime()
function with a few numbers.