Lokang 

Python and MySQL

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Creating Variables

Creating variables in Python is straightforward. Variables are containers for storing data values, and Python is a dynamically typed language, meaning you don't need to declare the type of a variable explicitly. The type is determined automatically based on the value you assign.

Here’s how you can create variables in Python:

1. Assigning a Value to a Variable

You can assign a value to a variable using the = operator.

# Integer variable
age = 25
# Float variable
price = 19.99
# String variable
name = "Alice"
# Boolean variable
is_student = True

2. Variable Naming Rules

  • Must start with a letter or an underscore (_): Variable names cannot start with a number or a symbol.
  • Case-sensitive: myVar and myvar are two different variables.
  • Can include letters, numbers, and underscores: You can use a combination of these in your variable names.
# Valid variable names
my_var = 10
_var2 = 5.5
varName = "example"
# Invalid variable names (will raise an error)
2nd_var = 10  # Starts with a number
my-var = 5.5  # Contains a hyphen

3. Reassigning Variables

Variables in Python can be reassigned to a new value, even if it’s a different data type.

x = 10        # x is an integer
x = "Hello"   # Now x is a string

4. Multiple Assignments

You can assign values to multiple variables in a single line.

a, b, c = 1, 2, "three"
# This will result in:
# a = 1
# b = 2
# c = "three"

5. Assigning the Same Value to Multiple Variables

You can also assign the same value to multiple variables at once.

x = y = z = 100

6. Dynamic Typing

Since Python is dynamically typed, the type of a variable can change during the program’s execution.

num = 5       # num is an integer
num = 5.5     # Now, num is a float
num = "Five"  # Now, num is a string

Example Usage

Here’s a simple example that demonstrates variable creation and reassignment:

# Creating variables
username = "JohnDoe"
score = 95
is_logged_in = True
# Printing variables
print(username)  # Output: JohnDoe
print(score)     # Output: 95
print(is_logged_in)  # Output: True
# Reassigning a variable
score = 100
print(score)  # Output: 100

This example shows how to create and manipulate variables in Python.



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