What does nameerror name is not defined mean python lessons learned

**tutorial: understanding nameerror - name is not defined in python**

in python, a `nameerror` occurs when you try to use a variable or a function that has not been defined or is not in the current scope. this error is very common, especially for beginners, and can be easily fixed once you understand its cause.

**causes of nameerror - name is not defined:**
1. **variable not defined:** if you try to use a variable that has not been defined, python will raise a `nameerror`.
2. **function not defined:** similarly, if you try to call a function that has not been defined, python will raise a `nameerror`.
3. **scope issue:** variables and functions need to be defined in the correct scope to be accessible. if you try to access a variable or function outside of its scope, a `nameerror` will be raised.

**lessons learned:**
1. always make sure to define variables and functions before using them.
2. check for typos in variable and function names.
3. understand the concept of scope and how it affects the accessibility of variables and functions.

**code example:**

by understanding the causes and solutions to `nameerror - name is not defined`, you can write cleaner and error-free python code. remember to always define your variables and functions in the correct scope and double-check for any typos in your code.

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