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Minor changes to nonlocal explanation
Closes https://github.com/satwikkansal/wtfpython/issues/193
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README.md
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README.md
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@ -1987,6 +1987,8 @@ Okay, now it's deleted :confused:
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### ▶ The out of scope variable
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<!-- Example ID: 75c03015-7be9-4289-9e22-4f5fdda056f7 --->
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1\.
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```py
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a = 1
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def some_func():
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@ -1995,8 +1997,10 @@ def some_func():
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def another_func():
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a += 1
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return a
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```
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2\.
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```py
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def some_closure_func():
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a = 1
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def some_inner_func():
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@ -2026,7 +2030,7 @@ UnboundLocalError: local variable 'a' referenced before assignment
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#### 💡 Explanation:
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* When you make an assignment to a variable in scope, it becomes local to that scope. So `a` becomes local to the scope of `another_func`, but it has not been initialized previously in the same scope, which throws an error.
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* To modify the outer scope variable `a` in `another_func`, use `global` keyword.
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* To modify the outer scope variable `a` in `another_func`, we have to use the `global` keyword.
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```py
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def another_func()
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global a
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@ -2039,8 +2043,8 @@ UnboundLocalError: local variable 'a' referenced before assignment
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>>> another_func()
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2
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```
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* In `another_closure_func`, `a` becomes local to the scope of `another_inner_func`, but it has not been initialized previously in the same scope, which is why it throws an error.
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* To modify the outer scope variable `a` in `another_inner_func`, use the `nonlocal` keyword.
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* In `another_closure_func`, `a` becomes local to the scope of `another_inner_func`, but it has not been initialized previously in the same scope, which is why it throws an error.
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* To modify the outer scope variable `a` in `another_inner_func`, use the `nonlocal` keyword. The nonlocal statement is used to refer to variables defined in the nearest outer (excluding the global) scope.
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```py
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def another_func():
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a = 1
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@ -2056,7 +2060,7 @@ UnboundLocalError: local variable 'a' referenced before assignment
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>>> another_func()
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2
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```
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* The keywords `global` and `nonlocal` are ways to simply tell the python interpreter to not delcare new variables, but to just look them up from the corresponding scope.
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* The keywords `global` and `nonlocal` tell the python interpreter to not delcare new variables and look them up in the corresponding outer scopes.
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* Read [this](http://sebastianraschka.com/Articles/2014_python_scope_and_namespaces.html) short but an awesome guide to learn more about how namespaces and scope resolution works in Python.
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---
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