NameError: Name plot_cases_simple Is Not Defined [SOLVED]

NameError: Name plot_cases_simple Is Not Defined error is a generic name error. This plot cases simple is just a placeholder.

This can be the name of a function, a variable, or a Python module. In this article, we’ll show you how to fix this error by giving plot cases simple as a dummy name.

What is NameError: Name plot_cases_simple Is Not Defined?

In Python, the NameError happens when you try to use a variable, function, or module that doesn’t exist or wasn’t used in a valid way.

Some of The Common Mistakes That Cause This Error are:

• Using a variable or function name that is yet to be defined.
• Misspelling a variable/function name when calling the variable/function.
• Using a Python module without importing the module, and so on.

How To Solve NameError: Name plot_cases_simple Is Not Defined?

In this section, you will learn how to fix the Python error “NameError: Name is Not Defined.” I’ve split this section into sub-sections to show the error above when using variables, functions, and modules.

• Example 1 – Variable Name Is Not Defined in Python
• Example 2 – Function Name Is Not Defined in Python
• Example 3 – Using a Module Without Importing the Module Error in Python

Example 1: Variable Name Is Not Defined in Python

name = "Jude"

print(age)


# This will be the Output:

#NameError: name 'age' is not defined

In the code above, we set up a variable called “name,” but we tried to print “age,” which hasn’t been set up yet.

We got an error that says: NameError: name ‘age’ is not defined. This means that the age variable doesn’t exist.

Example 1 Solution:

We can fix this by making the variable, and then our code will run correctly. Here’s an example of code:

name = "Jude"
age = 26
print(age)


# This will be the Output:
# 26

Example 2: Function Name Is Not Defined in Python

def sayHi():
    print("Hi IT SOURCECODE!")
    
sayHello()
# NameError: name 'sayHello' is not defined

In the above example, we used sayHello() instead of sayHi() to call the function ().

We got this error: NameError: name’sayHello’ is not defined. It’s easy to miss spelling mistakes like this. Most of the time, the error message will help you fix this.

Example 2 Solution:

def sayHi():
    print("Hi IT SOURCECODE!")
    
sayHi()
# This will be the output:
# Hi IT SOURCECODE!

Example 3 : Using a Module Without Importing the Module Error in Python

x = 5.5

print(math.ceil(x))

# This will be the output:
# NameError: name 'math' is not defined

In the above example, we use the Python math.ceil method without importing the math module.

NameError: name’math’ is not defined was the error message that came up. This happened because the math keyword was not known to the interpreter.

In Python, we must first import the math module before we can use it or any other math method.

Example 3 Solution:

import math

x = 5.5

print(math.ceil(x))
# 6

The math module was brought in on the first line of code. When you now run the code above, you should get the number 6 back.

Summary

In this article we discussed on how to fix NameError: Name plot_cases_simple Is Not Defined, we provide a different example program on how to fix the error. I hope this tutorial can help you a lot and can solve your problem.

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Inquiries

However, If you have any questions or suggestions about this tutorial NameError: Name plot_cases_simple Is Not Defined, Please feel to comment below, Thank You and God Bless!

Common use cases for NameError: Name plot_cases_simple Is Not Defined [SOLVED]

• Data pipelines. Python is the standard for ETL, data analysis, and ML workflows.
• Web development. Django and FastAPI power modern web backends and APIs.
• Automation and scripting. System administration, file processing, web scraping, and cron jobs.
• Machine learning. scikit-learn, PyTorch, TensorFlow, Hugging Face for AI/ML projects.
• Educational tools. Python’s readability makes it the go-to teaching language.

Working code example

from typing import Optional

def process_data(items: list[dict]) -> Optional[dict]:
    """Process a list of items and return summary stats."""
    if not items:
        return None
    return {
        "count": len(items),
        "total": sum(item.get("value", 0) for item in items),
        "avg": sum(item.get("value", 0) for item in items) / len(items),
    }

# Usage
data = [{"value": 10}, {"value": 20}, {"value": 30}]
summary = process_data(data)
print(summary)  # {'count': 3, 'total': 60, 'avg': 20.0}

Best practices

• Use type hints. list[dict], Optional[str], and TypedDict make code self-documenting and enable static analysis.
• Follow PEP 8. Consistent style improves readability. Use black or ruff to auto-format.
• Prefer f-strings. f”{value}” is cleaner than str.format() or % formatting.
• Write tests with pytest. Aim for 70%+ coverage on business-critical modules.
• Use ruff or pylint. Static analysis catches many bugs before code runs.

Common pitfalls

• Mutable default arguments. def f(x=[]) reuses the same list across calls. Use x=None then check.
• Integer division. 5/2 gives 2.5 in Python 3. Use // for floor division.
• Missing self on methods. Class methods need self as first parameter.
• Late binding closures. Loops that create lambdas can capture variables late.

Angel Jude Suarez

Full-Stack Developer at PIES IT Solution

Focuses on Python development, machine learning, and AI integration. Has built production AI systems including OpenAI Whisper integration for medical transcription and GPT-4o-powered diagnosis assistance. Strong background in pandas, scikit-learn, and TensorFlow.

Expertise: Python · PHP · Java · VB.NET · ASP.NET · Machine Learning · AI Integration · OpenCV · Django · CodeIgniter
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