Function¶
A function is a reusable block of code that performs a specific task.
Define a Function¶
def greet():
print("Hello Python!")
Call a Function¶
def greet():
print("Hello Python!")
greet()
Output¶
Hello Python!
Function with Parameters¶
Parameters allow you to pass data into a function.
def greet(name):
print("Hello", name)
greet("Alice")
Output¶
Hello Alice
Parameter Types¶
Python supports different kinds of parameters.
Positional Parameters¶
Arguments are matched to parameters by their position.
def introduce(name, age):
print(name, age)
introduce("Alice", 20)
Keyword Parameters¶
Arguments are matched by parameter name.
def introduce(name, age):
print(name, age)
introduce(age=20, name="Alice")
Default Parameters¶
Parameters can have default values.
def greet(name="Guest"):
print("Hello", name)
greet()
greet("Alice")
Output¶
Hello Guest
Hello Alice
Type Hints for Parameters¶
You can specify the expected parameter and return types using type hints.
def add(a: int, b: int) -> int:
return a + b
result = add(3, 5)
print(result)
Type hints improve code readability and help development tools detect errors, but they are not enforced at runtime by Python.
Summary¶
- Define functions with
def - Pass data using parameters
- Use positional, keyword, and default parameters
- Add type hints to document parameter and return types