Python Fundamentals

Introduction

Python is like the magician of the programming world - it can make your computer do incredible things with just a few lines of code.

IPO Cycle: Just like a magic show, Python follows the IPO cycle, which stands for Input, Processing, and Output. Think of it as a recipe: you gather ingredients (input), mix them up (processing), and finally, you get a delicious dish (output).

Are Programs Incorporated with IPO Cycle ? : Absolutely! Python is all about creating programs, which are basically sets of instructions for your computer. It's like teaching your computer some cool tricks.
Basic Elements

Character Set: Python speaks a language made up of characters, kind of like the alphabet. It understands letters, numbers, and symbols. So, if you can type it, Python can understand it!

Tokens: These are like the building blocks of Python. Words, numbers, and symbols are tokens. Imagine them as the LEGO bricks of your code.

Expressions: Think of expressions as little math equations Python can solve. It's like asking Python to calculate the answer to 2 + 2, and it replies with 4. Magic, right?

Statements: These are like sentences in Python. You give your computer a command, and it follows your instructions. For example, telling it to print "Hello, World!" is a statement.

Simple Input and Output: Python can talk to you and listen to you! It can take your words as input and speak its mind as output. So, you can ask it questions, and it will respond.

So, in a nutshell, Python is a fun and versatile programming language. It uses the IPO cycle to create programs, understands a wide range of characters, uses tokens as building blocks, solves expressions like a math whiz, follows your instructions through statements, and can even chat with you through input and output. It's like having a digital wizard at your command! 🎩💻✨

Python Character set

Python's character set refers to the collection of characters it can understand and use in your code. Python primarily uses the Unicode character set, which is a vast character encoding standard that includes characters from multiple languages and scripts. Here are some examples of Python's character set:


1. Letters: Python recognizes both uppercase and lowercase letters from the English alphabet and many other alphabets from different languages. For example:

Letters

 
a = 'Hello' 
b = 'World' 
    

2. Numbers: Python understands numeric characters, including digits from 0 to 9. You can use them in calculations and to represent numerical values:

Numbers

x = 42 # Integer
y = 3.14 # Float
      

3. Symbols: Python recognizes various symbols and punctuation marks, which are essential for code structure and syntax. Some examples include:

Symbols

      
+ # Addition Operator
        
- # Subtraction Operator
        
* # Multiplication operator
        
/ # Division operator
        
% # Modulo operator (remainder after division)
        
= # Assignment operator
        
== # Equality comparison operator (checks if two values are equal)
        
!= # Inequality comparison operator (checks if two values are not equal)
        
< # Less than comparison operator
        
> # Greater than comparison operator
        
<= # Less than or equal to comparison operator
        
>= # Greater than or equal to comparison operator
        
( # Left parenthesis, used for grouping and function calls
        
) # Right parenthesis, used to close groups and function calls
        
[ ] # Square brackets, used for creating arrays or accessing elements in arrays
        
{ } # Curly braces, used for defining blocks of code and creating objects in some programming languages (e.g., JavaScript)
        
, # Comma, used to separate items in a list or arguments in a function call
        
: # Colon, used in various ways, such as in Python for defining key-value pairs in dictionaries or in JavaScript for labeling statements
        
        
. # Period or Dot, used for accessing properties or methods of objects in object-oriented programming
        
... # Ellipsis, used in some languages (e.g., Python) to indicate a continuation or a placeholder in code
         

4. Whitespace Characters: Python uses spaces, tabs, and newline characters to format and structure code:

Whitespace Characters

indentation = 4
new_line = '\n'
      

5. Escape Sequence Characters: Python also supports special characters and escape sequences. For instance:

Escape Sequence Characters

\n # Represents a newline character.
\t # Represents a tab character.
\" and \' # Used to include double or single quotes inside strings.
\\ # Represents a literal backslash character.

# Consider the below Example to demonstrate
a = "Vibrantnotes provide best notes!\nThanks!
print(a)

Output:
Vibrantnotes provide best notes!
Thanks!
      

6. Unicode Characters: Python can handle a wide range of Unicode characters, allowing you to work with text in various languages and even include emojis and special symbols in your code:

Numbers

emoji = "🐍"
pi = "π"
      

Tokens

Tokens in Python are the smallest units of a program, similar to words in a sentence. They are the building blocks of Python code and are used to represent different elements like keywords, identifiers, operators, and literals.

Tokens are separated by whitespace, such as spaces or tabs. Let's explore some examples and types of tokens:

Tokens in English Sentence
Click the image for clear view

Tokens in Python program
Click the image for clear view

1. Keywords: Keywords are reserved words in Python that have special meanings and cannot be used as variable names. Examples include `if`, `else`, `while`, `for`, `def`, and `import`.

Numbers

if x>5:
     print("x is greater than 5")
      

2. Identifiers: Identifiers are user-defined names for variables, functions, classes, etc. They must follow certain rules, like starting with a letter or underscore and consisting of letters, digits, and underscores. For example, my_variable, calculate_area, or _private_variable.

Numbers

age = 30
name = "Alice"
      

3. Operators: Operators are symbols used to perform operations on variables and values. Examples include +, -, *, /, ==, !=, >, and, "and".

Numbers

result = 10 + 5
is_equal = (x == y)
      

4. Literals: Literals are values that are directly represented in code. There are several types of literals in Python: 

• Numeric Literals (integers and floating-point numbers):

Numeric Literals 

count = 42
pi = 3.14159
      

• String Literals (text enclosed in single or double quotes):

String Literals

message = "Hello, World!"
      

• Boolean Literals (True and False):

Boolean Literals

is_raining = True
is_sunny = False
      

• None Literal (None represents the absence of a value):

None Literal 

empty_variable = None
      

5. Delimiters: Delimiters are characters that define the structure of code. Common delimiters include parentheses (), square brackets [], and curly braces {} for grouping and organizing code blocks.