stev-star / python-basics

This repository contains an Article and Two project that is Prime numbers and Fibonacci sequence

Python-Basics

This repository contains an Python Article

Introduction To Python Programming

Python is a high-level,geneal-purpose,interpreted programming language which was created by Guido Van Rossum and released in 1991.

It is dynamically-typed and garbage-collected and it supports multiple programming paradigms which include procedural, object-oriented and fuctional programming.

Why learn Python?

• it is beginner friendly-Python is a great language for the beginner-level programmers and supports the development of a wide range of applications.
• python is interpreted-Python is processed at runtime by the interpreter.
• python is object-oriented - Python supports Object-Oriented technique of programming that encapsulates code within objects.
• python is interactive - You can actually sit at a Python prompt and interact with the interpreter directly to write your programs.

Characteristics of Python

• It can be easily integrated with other programming languages such as C,C++,Java e.t.c.
• It provides high-level-Python is a high-level programming language because programmers don’t need to remember the system architecture, nor do they have to manage the memory.
• Object-Oriented - it focuses design around data and objects, rather than functions and logic.
• extensive standard library - programmers don’t have to write their code for every single thing unlike other programming languages.
• Free and Open-Source - it is completely free to use, even for commercial purposes.

Applications of Python

• Web Development
• Machine Learning and Artificial intelligence
• Data Science
• Audio and Visual Application
• Software Dvelopment
• Desktop GUI
• Web Scraping Application

Python Hello World

Here's how to create a python program that displays "Hello World!"

print("Hello World!")

The print() is a built-in function that displays a message on the screen

Python Identation

Indentation refers to the spaces at the beginning of a code line.

Where in other programming languages the indentation in code is for readability only, the indentation in Python is very important.

Python uses indentation to indicate a block of code.

for i in range(5):
  print(i)

Comments

Comments start with a #, and Python will render the rest of the line as a comment

#This is a programm to display "Hello World!"

print("Hello World!")

Variables

A Python variable is a reserved memory location to store values. In other words, a variable in a python program gives data to the computer for processing.

num=100 
print(num) # 100
place=’Nyahururu’ 
print(place) # Nyahururu

Python Operators

Arithmetic Operators:

+, -, /, *, % ,//, **

Comparison operators:

, <, ==, !=, <=, >=

Logical operators:

and, or, not

Bitwise operators:

<<, |, &, ~, ^, >>

Assignment Operator:

=, +=, -=, /=, *=

Identity operators:

is, is not

Membership operators:

in, not in

Data types in Python

• Numbers

Python includes three numeric types to represent numbers: integers, float, and complex number.

amount=1000 # integer
print(f"Amount provided is ksh{amount}") # Amount provided is ksh1000
quantity=12.5 # float
print(f"The required quantity is {quantity}L") # The required quantity is 12.5L
value= 1+5j # complex
print(f"The solution is {value}") # The solution is (1+5j)

• Strings

Strings are sequences of character data. The string type in Python is called str. String literals may be delimited using either single or double quotes.

 greeting =("Hello There")
 print(greeting) # Hello There
    
 name1="py"
 name2="thon"
 print(name1 + name2) # python
    
 person=("Kim")
 print(f"Hello {person}")

• Boolean

Python boolean type is one of the built-in data types provided by Python, which represents one of the two values i.e. True or False.

print(10 > 9) # True
print(6 ==3) # False
print(15 < 11) # False

• List

  Lists are a built-in data type in Python, and one of the most powerful data structures. They act as containers and store multiple, typically related, items under the same variable name. Items are placed and enclosed inside square brackets, []. Each item inside the square brackets is separated by a comma, ,.

colors=['green','red','blue']
colors.append('yellow')
print(colors) # ['green', 'red', 'blue', 'yellow']
colors.insert(4,'black')
print(colors) # ['green', 'red', 'blue', 'yellow', 'black']
del colors[1]
print(colors) # ['green', 'blue', 'yellow', 'black']
colors.pop()
print(colors) # ['green', 'blue', 'yellow']
colors.remove('blue')
print(colors) # ['green', 'yellow']

• Tuple

A Tuple is a collection of Python objects separated by commas. In someways a tuple is similar to a list in terms of indexing, nested objects and repetition but a tuple is immutable unlike lists which are mutable. items are enclosed inside brackets ().

rgb=('red','green','blue')
print(rgb) # ('red', 'green', 'blue')
print(rgb[0]) # red

• Dictionary

Dictionary in Python is an unordered collection of data values, used to store data values like a map, which, unlike other Data Types that hold only a single value as an element, Dictionary holds key:value pair. The first way is by using a set of curly braces, {}, and the second way is by using the built-in dict() function.

person={'name':'john',
'age':21,
'country':'Kenya',
'programming_language':'Python'}
print(person['age']) # 21
print(person['name'] # john

# adding a new key-value
person['Hobby']='Swimming'
# deleting a key-value
del person['country']

• Set

Set is an unordered collection of data type that is iterable, mutable and has no duplicate elements. The order of elements in a set is undefined though it may consist of various elements. Sets are written with curly brackets {}.

fruits={"apple", "banana", "cherry","mango","pawpaw","pineapple"}
print(fruits)

# adding a fruit
fruits.add('watermelon')
# removing a fruit
fruit.remove('pawpaw')
fruit.discard('cherry')
# removing all elements
fruits.clear() # set()