This answer was entirely written by a human:
There is a "NameError" in Python, which means when a script refers to a variable, function, or module that has not been defined or imported, it causes a NameError in Python. For Power BI, this could happen for several reasons. Here are some of them:
Undefined Variables: All variables should be initialized correctly and have the assigned value when trying to use them. For instance, using a variable x when it has not yet been defined will throw a NameError. Verify the referencing script to confirm if all your variables are declared and assigned properly.
Incorrect Imports of Libraries: When your script has imported external libraries (pandas, matplotlib), ensure that those libraries are installed in the configured Python environment for Power BI. To check, open the command prompt or terminal and run the pip list to ensure that all required libraries are there. Another consideration is whether you have used the correct import statement, such as import pandas as pd.
Mismatched Python Environments: Power BI uses a particular Python environment to execute a script. Therefore, if you have installed Python from more than one source (for instance, Anaconda with standalone Python), Power BI may point to the wrong one. Check the Options > Python scripting in Power BI, and verify whether the chosen path for Python goes to the environment where the required libraries are installed.
To resolve this, first isolate the error. Print or debug using an IDE like Visual Studio Code or Jupyter Notebook outside of Power BI, then reload the script into Power BI once it has been resolved.
