Nameerror name data is not defined [SOLVED]

Experiencing a nameerror name data is not defined, error message while you are working with Python Pandas?

Yet, you are struggling to fix this error because you’re not familiar with it?

Worry no more as we’ll hand you the effective solutions for nameerror: name ‘data’ is not defined.

But before we dive into the solution, let’s first understand what this error means and why it occurs in your Python script.

What is “nameerror name data is not defined”?

The error message nameerror: name ‘data’ is not defined occurs when you try to execute a Pandas operation on a DataFrame or Series that has not been loaded into memory.

For instance, if you try to perform an operation like sorting, filtering, or grouping on a DataFrame that has not been defined, you will get this error message.

Here’s the example code that results in this error.

import pandas as pd

def my_function():
    df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
    print(data.head())

my_function()

If you run this code, technically you’ll get this error message.

NameError: name 'data' is not defined

This is because the interpreter fails to recognize a variable or object that has not been defined or initialized in the current scope.

In addition to that, this error usually happens when you try to perform an operation on a variable that has not been declared or assigned a value.

What are the root cause of this error?

There are several root causes of this nameerror: name ‘data’ is not defined error message, including:

❌ The variable or object has not been defined in the current scope.

❌ The variable or object is defined in a different scope, such as a function or class, and is not accessible in the current scope.

❌ A simple typo in the variable or object name can also cause this error.

❌ The error can also be caused by incorrect use of Python keywords.

❌ If you try to access a variable or object before it is defined or initialized, this error can occur.

How to fix “nameerror name data is not defined”?

To fix this error, you have to make sure that you already defined and initialized the variable or object before performing any operation on it.

The easiest way to do this is to load the data into a DataFrame or Series object.

Here are the following solutions that you can use to fix this error.

1. Define the variable or object

If the error is caused by the variable or object not being defined in the current scope, you can define it within the function or method where it is being used.

For instance, you can modify the code to define df outside of the function so that it is accessible within the function:

✅ import pandas as pd

df = pd.DataFrame({'Example1': [1, 2, 3, 4, 5], 'Example2': [10, 20,30, 40, 50]})

def sample_function():
    print(df.head())

sample_function()

In that way, df is defined in the global scope and can be accessed within the sample_function() function.

As you can see, in the example code above, we change the data.head() into df.head() would fix the error.

Output:

   Example1  Example2
0         1        10
1         2        20
2         3        30
3         4        40
4         5        50

2. Load data

Rather than defining and initializing the variable manually, you can load the data from a file using the read_csv() function or other functions provided by Pandas.

✅ import pandas as pd

df = pd.read_csv('data.csv')
print(df)

Output:

   feature1  feature2  target
0         1         3       8
1         2         5      12
2         3         7      15
3         4         8      18
4         5        10      20

3. Pass the data as a parameter

Alternatively, you can also pass the data as a parameter to a function or method that expects a DataFrame or Series object, rather than defining and initializing the variable manually.

For example:

✅ import pandas as pd

def my_function(data):
    df = pd.DataFrame(data)
    return df

data = [10, 20, 30, 40, 50]
df = my_function(data)
print(df)

Output:

Frequently Asked Questions (FAQs)

Does this error only occur in Pandas?

No, this error can occur in any Python code when a variable or object has not been defined or initialized in the current scope.

The “nameerror: name ‘data’ is not defined” error be prevented?

Yes, you can prevent this error by ensuring that you have defined and initialized the variable or object before performing any operation on it.

Conclusion

In conclusion, the error message nameerror: name ‘data’ is not defined occurs when you try to execute a Pandas operation on a DataFrame or Series that has not been loaded into memory.

This article explore what this error is all about and already provides solutions to help you fix this error.

You could also check out other “nameerror” articles that may help you in the future if you encounter them.

We are hoping that this article helps you fix the error. Thank you for reading itsourcecoders 😊