Why nested functions can access variables from outer functions, but are not allowed to modify them [duplicate] Why nested functions can access variables from outer functions, but are not allowed to modify them [duplicate] python python

Why nested functions can access variables from outer functions, but are not allowed to modify them [duplicate]


python scope

In Python 3.x this is possible:

def f1():        x = 5        def f2():                nonlocal x                x+=1        return f2

The problem and a solution to it, for Python 2.x as well, are given in this post. Additionally, please read PEP 3104 for more information on this subject.

python scope 

def f1():    x = { 'value': 5 }    def f2():        x['value'] += 1

Workaround is to use a mutable object and update members of that object. Name binding is tricky in Python, sometimes.

Recent Posts
How can I color dots in a xy scatterplot according to column value?
How to update a claim in ASP.NET Identity?
What does {0} mean when initializing an object?
Accessing members of items in a JSONArray with Java
How to log SQL statements in Spring Boot?
Powershell Get-WebSite name parameter is ignored
How to detect scroll to bottom of html element
Java synchronized method
How to test controllers with CodeIgniter?
Detect Visual Composer
Matplotlib: Specify format of floats for tick labels
Rails join a list of strings with commas and "and" before the last