Python Error: Name 'd' Not Defined

When learning Python, it's common to encounter errors that can be difficult to pinpoint. Consider the following example from Python 3 for Absolute Beginners:

Name = ""
Desc = ""
Gender = ""
Race = ""
# Prompt user for user-defined information
Name = input('What is your Name? ')
Desc = input('Describe yourself: ')

When executed, this code expects the user to enter a value for their name, which they input as 'd'. However, the program responds with the error:

NameError: name 'd' is not defined

Understanding the Error:

In Python 2.x, the input() function treats 'd' as a Python expression, interpreting it as a variable named 'd'. However, since 'd' has not been defined within the program, it triggers a NameError.

Solution:

To resolve this error, consider two approaches:

1. Using raw_input() in Python 2.x:

In Python 2.x, raw_input() returns the entered value as a raw string, preventing it from being interpreted as an expression.

# Python 2.x
Name = raw_input('What is your Name? ')

2. Upgrading to Python 3.x:

Python 3.x introduced a unified input() function that behaves consistently with raw_input() from Python 2.x. Therefore, using Python 3.x would eliminate the need for raw_input() in this scenario.

# Python 3.x
Name = input('What is your Name? ')