Basic Python Tutorial for Beginners
Python is an easy-to-learn programming language, making it perfect for beginners. This guide covers foundational topics like variables, data types, input/output, and operators to get you started.
Variables and Data Types
What is a Variable?
A variable is a named container for storing data values. In Python, you don’t need to declare the type of variable; it is dynamically inferred.
Examples of Variables:
# Variable declaration
x = 10 # Integer
name = "Alice" # String
is_active = True # Boolean
Data Types in Python
Python supports several basic data types:
Data Type | Example | Description |
---|---|---|
Integer | 10 , -3 | Whole numbers |
Float | 3.14 , -2.5 | Decimal numbers |
String | "Hello" , 'A' | Sequence of characters |
Boolean | True , False | Represents truth values |
Example of Data Types:
age = 25 # Integer
height = 5.9 # Float
greeting = "Hi there" # String
is_logged_in = False # Boolean
Numbers, Strings, and Booleans
Numbers
- Integers and floats are used for arithmetic.
- Example
a = 10
b = 3.5
print(a + b) # Output: 13.5
Strings
- Strings can be enclosed in single (
'
) or double ("
) quotes. - Example:
message = "Python is fun!"
print(message) # Output: Python is fun!
Booleans
- Represent truth values (
True
orFalse
). - Example:
is_sunny = True
print(is_sunny) # Output: True
Type Conversion
Convert between data types using built-in functions:
int()
: Converts to integer.float()
: Converts to float.str()
: Converts to string.
Example:
# Implicit type conversion
a = 10
b = 3.5
result = a + b # Automatically converts to float
# Explicit type conversion
age = "25"
age_int = int(age) # Converts string to integer
print(age_int + 5) # Output: 30
Basic Input/Output
Input:
- Use
input()
to get user input as a string. - Example:
name = input("Enter your name: ")
print("Hello, " + name + "!")
Output:
- Use
print()
to display output. - Example:
print("Welcome to Python!")
Formatted Strings:
- Use f-strings for easy string formatting.
- Example
age = 25
print(f"I am {age} years old.") # Output: I am 25 years old.
Operators in Python
Arithmetic Operators
Operator | Description | Example |
---|---|---|
+ | Addition | a + b |
- | Subtraction | a - b |
* | Multiplication | a * b |
/ | Division | a / b |
// | Floor Division | a // b |
% | Modulus (remainder) | a % b |
** | Exponentiation | a ** b |
Example:
python
x = 10
y = 3
print(x + y) # Output: 13
print(x // y) # Output: 3
Comparison Operators
Operator | Description | Example |
---|---|---|
== | Equal to | a == b |
!= | Not equal to | a != b |
> | Greater than | a > b |
< | Less than | a < b |
>= | Greater than or equal to | a >= b |
<= | Less than or equal to | a <= b |
Example:
a = 5
b = 10
print(a > b) # Output: False
print(a <= b) # Output: True
Logical Operators
Operator | Description | Example |
---|---|---|
and | Returns True if both are True | a and b |
or | Returns True if one is True | a or b |
not | Reverses the Boolean value | not a |
Example:
a = True
b = False
print(a and b) # Output: False
print(a or b) # Output: True
Assignment Operators
Operator | Description | Example |
---|---|---|
= | Assign | x = 5 |
+= | Add and assign | x += 3 |
-= | Subtract and assign | x -= 3 |
*= | Multiply and assign | x *= 3 |
/= | Divide and assign | x /= 3 |
Example:
x = 10
x += 5 # x = x + 5
print(x) # Output: 15
Best Practices for Beginners
Use Descriptive Variable Names:
- Instead of
x
ory
, use names likeage
orprice
.
- Instead of
Comment Your Code:
- Add comments to explain the purpose of code snippets.
Test Frequently:
- Run your code after small changes to catch errors early.
Learn Error Messages:
- Understand Python errors like
SyntaxError
orNameError
to debug effectively.
- Understand Python errors like
Practice Daily:
- Consistent practice helps reinforce learning.