A definition in Python refers to the creation of a variable, function, class, or any other data structure. It includes assigning values to variables, defining the body of functions, methods, or classes. Essentially, defining something means providing its complete structure and behavior.
x = 10
y = "Hello, World!"
def greet(name):
return f"Hello, {name}!"
class Person:
def __init__(self, name, age):
self.name = name
self.age = age
def get_info(self):
return f"{self.name} is {self.age} years old."
my_list = [1, 2, 3, 4, 5]
In some programming languages, a declaration refers to announcing the existence of a variable, function, or class without necessarily providing its complete definition. However, in Python, the concept of declaration is less explicit because Python is dynamically typed and does not require variable type declarations.
In Python, defining a variable or function also serves as its declaration because you don’t separately declare their types.
count = 0
message = "Welcome to Python!"
def add(a, b):
return a + b
class Animal:
def __init__(self, species):
self.species = species
def speak(self):
return "Some generic sound"
Dynamic Typing: Python does not require explicit type declarations because it uses dynamic typing. The type of a variable is determined at runtime.
No Separate Declarations: Unlike some other languages (like C or Java), Python does not have separate variable or function declarations. Definitions in Python inherently serve as declarations.
Implicit Declaration: When you define a variable, function, or class in Python, you implicitly declare it.