Nameerror: Name Plot_Cases_Simple Is Not Defined in Python

Python, being a dynamically typed language, often encounters the “NameError: name ‘plot_cases_simple’ is not defined.” This error arises when you attempt to use a variable or function that Python cannot recognize in the current scope. In this article, we will explore the meaning of this error, understand why it occurs, and provide solutions to rectify it.

What is NameError: Name ‘plot_cases_simple’ is Not Defined?

The NameError is a common exception in Python, signaling that a variable or function with the specified name is not defined in the current scope. In the context of “Name ‘plot_cases_simple’ is not defined,” it indicates that Python cannot find a reference to the variable or function plot_cases_simple where it is being used.

Why does NameError: Name ‘plot_cases_simple’ is Not Defined Occur?

Below are some of the reasons due to why NameError: Name ‘plot_cases_simple’ is Not Defined occurs in Python:

• Undefined Variable
• Incorrect Scope
• Typos or Case Sensitivity

Undefined Variable

The most straightforward reason is that you have not defined the variable or function plot_cases_simple in your code before attempting to use it.

Python3

# Plot_Cases_Simple is not defined here
print(plot_cases_simple)  # This will raise a NameError

Output:

Hangup (SIGHUP)
Traceback (most recent call last):
  File "Solution.py", line 2, in <module>
    print(Plot_Cases_Simple)  # This will raise a NameError
NameError: name 'plot_cases_simple' is not defined

Incorrect Scope

If plot_cases_simple is defined inside a function or a conditional block, trying to access it outside that scope will result in a NameError.

Python3

def my_function():
    plot_cases_simple = 42

print(plot_cases_simple)  # This will raise a NameError

Output:

Hangup (SIGHUP)
Traceback (most recent call last):
  File "Solution.py", line 4, in <module>
    print(Plot_Cases_Simple)  # This will raise a NameError
NameError: name 'plot_cases_simple' is not defined

Typos or Case Sensitivity

Check for typos in the variable or function name. Python is case-sensitive, so plot_cases_simple and plot_cases_simple are treated as distinct entities.

Python3

# Correct usage
plot_case_simple = 42
print(plot_cases_simple)

Output:

Hangup (SIGHUP)
Traceback (most recent call last):
  File "Solution.py", line 3, in <module>
    print(Plot_Case_Simple)
NameError: name 'plot_cases_simple' is not defined

Fix NameError: Name ‘plot_cases_simple’ is Not Defined

Below are some of the solution for this error:

• Define the Variable or Function
• Check Scope
• Correct Typos and Case Sensitivity

Define the Variable or Function

Ensure that you have defined plot_cases_simple before attempting to use it.

Python3

# Correct usage
plot_cases_simple = 42

print(plot_cases_simple)

Output

42

Check Scope

Verify that you are trying to use plot_cases_simple within the correct scope. If it’s defined inside a function, use it within that function.

Python3

def my_function():
    plot_cases_simple = 42
    print(plot_cases_simple)  # This will work

my_function()

Output

42

Correct Typos and Case Sensitivity

Double-check the spelling and case of the variable or function name.

Python3

# Correct usage
plot_cases_simple = 42

print(plot_cases_simple)

Output

42