How to Fix – NameError: name ‘pprint’ is not defined

If you are a Python developer, you may have encountered the error message “NameError name ‘pprint’ is not defined” while working with the pprint module in Python. In this tutorial, we will explore the possible causes of this error and provide step-by-step instructions on how to fix it.

We will cover common causes of the error and provide solutions to help you get your code up and running quickly. So, let’s get started!

Why does the NameError: name 'pprint' is not defined error occur?

This error occurs when you try to use the pprint library in your Python code, but Python cannot find the pprint module in its namespace. The following are some of the scenarios in which this error usually occurs.

1. You have not imported the pprint module.
2. You have imported the pprint module using a different name or are not using the correct function inside the pprint module.

How to fix the NameError: name 'pprint' is not defined?

The pprint module in Python stands for “pretty-print” and provides a way to format and display complex data structures in a more readable and organized way. It is particularly useful when working with nested data structures such as dictionaries and lists. Since this library is part of the Python Standard Library, you don’t need to separately install it. You can simply import it and start using it.

The pprint module provides a pprint() function that takes a Python object as input and outputs a formatted representation of the object as a string. The output is designed to be easy to read and understand, with each element of the data structure on a separate line and nested elements indented to show their relationship to the parent element.

Let’s now look at the above scenarios that may result into the above error in detail.

The pprint module is not imported

It can happen that you are trying to use the pprint module without even importing it. This is because Python does not recognize the pprint library and its functions until it is imported into the code.

For example, let’s try to use the pprint module without importing it and see what we get.

# note that pprint is not imported

# define a dictionary with nested lists and dictionaries
data = {
    'name': 'John',
    'age': 30,
    'hobbies': ['reading', 'coding', 'hiking'],
    'address': {
        'street': '123 Main St',
        'city': 'Anytown',
        'state': 'CA',
        'zip': '12345'
    }
}

# use pprint to pretty-print the data
pprint.pprint(data)

Output:

---------------------------------------------------------------------------

NameError                                 Traceback (most recent call last)

Cell In[1], line 17
      4 data = {
      5     'name': 'John',
      6     'age': 30,
   (...)
     13     }
     14 }
     16 # use pprint to pretty-print the data
---> 17 pprint.pprint(data)

NameError: name 'pprint' is not defined

We get a NameError stating that the name pprint is not defined. To use the pprint library, you need to import it first.

import pprint

# define a dictionary with nested lists and dictionaries
data = {
    'name': 'John',
    'age': 30,
    'hobbies': ['reading', 'coding', 'hiking'],
    'address': {
        'street': '123 Main St',
        'city': 'Anytown',
        'state': 'CA',
        'zip': '12345'
    }
}

# use pprint to pretty-print the data
pprint.pprint(data)

Output:

{'address': {'city': 'Anytown',
             'state': 'CA',
             'street': '123 Main St',
             'zip': '12345'},
 'age': 30,
 'hobbies': ['reading', 'coding', 'hiking'],
 'name': 'John'}

Here, we are importing the pprint module first and then using it to pretty print our nested dictionary. You can see that we did not get any errors here.

Note that the pprint() function is defined in the pprint module. This could be confusing because they both have the same name. If you want to use the pprint() function, you can either use the above syntax of importing the entire pprint module and then using pprint.pprint() function or you could only import the pprint() function like in the example below.

from pprint import pprint

# define a dictionary with nested lists and dictionaries
data = {
    'name': 'John',
    'age': 30,
    'hobbies': ['reading', 'coding', 'hiking'],
    'address': {
        'street': '123 Main St',
        'city': 'Anytown',
        'state': 'CA',
        'zip': '12345'
    }
}

# use pprint to pretty-print the data
pprint(data)

Output:

{'address': {'city': 'Anytown',
             'state': 'CA',
             'street': '123 Main St',
             'zip': '12345'},
 'age': 30,
 'hobbies': ['reading', 'coding', 'hiking'],
 'name': 'John'}

We get the same result.

The pprint module is imported using a different name

If you import the pprint module using a different name, for example import pprint as pp, and then try to use the name “pprint” to use it, you will get a NameError because the name “pprint” is not defined in your current namespace.

Let’s look at an example.

import pprint as pp

# define a dictionary with nested lists and dictionaries
data = {
    'name': 'John',
    'age': 30,
    'hobbies': ['reading', 'coding', 'hiking'],
    'address': {
        'street': '123 Main St',
        'city': 'Anytown',
        'state': 'CA',
        'zip': '12345'
    }
}

# use pprint to pretty-print the data
pprint.pprint(data)

Output:

---------------------------------------------------------------------------

NameError                                 Traceback (most recent call last)

Cell In[1], line 17
      4 data = {
      5     'name': 'John',
      6     'age': 30,
   (...)
     13     }
     14 }
     16 # use pprint to pretty-print the data
---> 17 pprint.pprint(data)

NameError: name 'pprint' is not defined

We get a NameError: name 'pprint' is not defined. This is because we have imported the pprint module with the name pp but we’re trying to use it using the name pprint.

To fix this error, you can either access pprint using the name that you have used in the import statement or import pprint without an alias.

import pprint as pp

# define a dictionary with nested lists and dictionaries
data = {
    'name': 'John',
    'age': 30,
    'hobbies': ['reading', 'coding', 'hiking'],
    'address': {
        'street': '123 Main St',
        'city': 'Anytown',
        'state': 'CA',
        'zip': '12345'
    }
}

# use pprint to pretty-print the data
pp.pprint(data)

Output:

{'address': {'city': 'Anytown',
             'state': 'CA',
             'street': '123 Main St',
             'zip': '12345'},
 'age': 30,
 'hobbies': ['reading', 'coding', 'hiking'],
 'name': 'John'}

In the above example, we are importing pprint as pp and then using pp to access the pprint module’s methods.

Alternatively, as seen in the example in the previous section, you can import pprint without any aliases and simply use pprint to avoid the NameError.

Conclusion

In conclusion, encountering a NameError: name 'pprint' is not defined error can be frustrating, but it is a common issue that can be easily fixed. By ensuring that the pprint module is imported correctly and that the correct syntax is used when calling its functions, you can avoid this error and successfully execute your code.

You might also be interested in –

• How to Fix – NameError name ‘statistics’ is not defined
• How to Fix – NameError name ‘random’ is not defined