~Hello, dear readers! Welcome back to our Python syntax series. We hope you found our previous articles on Python Basic Syntax and Comments insightful. If you missed them, we encourage you to give them a read to solidify your understanding of Python's foundational concepts. In this article, we will explore the world of variables in Python. Variables are essential for storing and manipulating data in any programming language. Let's dive in and discover the ins and outs of working with variables in Python!
Summary of Previous Articles: In our previous articles, we covered the basic syntax of Python, including the first Python program, identifiers, reserved words, lines and indentation, multiline statements, and comments. Understanding these concepts is crucial as we delve deeper into Python programming. If you haven't read those articles, we recommend taking a look to build a strong foundation.
1) Creating Python Variables:
In Python, variables are created by assigning a value to a name. Unlike other programming languages, you don't need to explicitly declare the type of the variable. Python automatically determines the type based on the assigned value.
Example:
name = "John"
age = 25
pi = 3.14
In the above example, we created three variables: name, age, and pi. The values assigned to the variables can be strings, integers, floats, or other data types.
2) Printing Python Variables:
To display the value of a variable, you can use the print() function in Python. It allows you to output the value of one or more variables to the console.
Example:
name = "John"
age = 25
print(name)
print(age)
The above code will output the values of the name and age variables to the console.
3) Deleting a Variable:
In Python, you can delete a variable using the del keyword. Once a variable is deleted, its name and value are removed from memory.
Example:
name = "John"
del name
After executing the above code, the variable name will no longer exist.
4) Multiple Assignments:
Python allows you to assign values to multiple variables in a single line, using a process called multiple assignment. This can be useful when initializing multiple variables with the same value or swapping variable values.
Example:
x = y = z = 10
a, b, c = 1, 2, 3
In the first line, all three variables x, y, and z is assigned the value 10. In the second line, the variables a, b, and c are assigned the values 1, 2, and 3, respectively.
5) Python Variable Names (Rules):
When naming variables in Python, there are a few rules to follow:
Variable names are case-sensitive (
myVarandmyvarare different variables).Variable names can contain letters, digits (0-9), and underscores (_).
The first character of a variable name cannot be a digit.
Variable names cannot be a reserved words or contain any special characters.
6) Python Local Variables:
In Python, variables defined inside a function have local scope. They are accessible only within the function where they are defined.
Example:
def my_function():
x = 10 # Local variable
print(x)
my_function()
In the above code, x is a local variable that can only be accessed within the my_function().
7) Python Global Variables:
Global variables
are defined outside any function and can be accessed from any part of the program. To access a global variable inside a function, you need to use the global keyword.
Example:
x = 10 # Global variable
def my_function():
global x
print(x)
my_function()
In the above code, the global keyword allows the function to access the global variable x.
Conclusion:
Understanding variables is fundamental to any programming language, and Python is no exception. In this article, we explored the creation of variables, printing their values, deleting variables, multiple assignments, variable naming rules, and the concepts of local and global variables. By mastering these concepts, you have gained a solid foundation for working with variables in Python.
Happy coding with Python!