We’ve previously seen how to create a nested function in Python.
If you return a nested function from a function, that nested function has access to the variables defined in that function, even if that function is not active any more.
Here is a simple counter example.
def counter():
count = 0
def increment():
nonlocal count
count = count + 1
return count
return increment
increment = counter()
print(increment()) # 1
print(increment()) # 2
print(increment()) # 3
We return the increment()
inner function, and that has still access to the state of the count
variable even though the counter()
function has ended.
More python tutorials:
- Introduction to Python
- Installing Python 3 on macOS
- Running Python programs
- Python 2 vs Python 3
- The basics of working with Python
- Python Data Types
- Python Operators
- Python Strings
- Python Booleans
- Python Numbers
- Python, Accepting Input
- Python Control Statements
- Python Lists
- Python Tuples
- Python Sets
- Python Dictionaries
- Python Functions
- Python Objects
- Python Loops
- Python Modules
- Python Classes
- The Python Standard Library
- Debugging Python
- Python variables scope
- Python, accept arguments from command line
- Python Recursion
- Python Nested Functions
- Python Lambda Functions
- Python Closures
- Python Virtual Environments
- Use a GoPro as a remote webcam using Python
- Python, how to create a list from a string
- Python Decorators
- Python Docstrings
- Python Introspection
- Python Annotations
- Python, how to list files and folders in a directory
- Python, how to check if a number is odd or even
- Python, how to get the details of a file
- Python, how to check if a file or directory exists
- Python Exceptions