Why are Python exceptions named \\\"Error\\\" (e.g. ZeroDivisionError, NameError, TypeError)?

In Python, exception names usually end with "Error" (like ZeroDivisionError, NameError, and TypeError). This clearly shows that they are related to problems that happen while the program is running. Using this naming style makes error messages easier to read, helps with debugging.

Why exceptions end with "Error"

An exception is a kind of (run-time) error. Having the word "Error" in the name of the exception may help us realize that there is an issue when we encounter an exception. It follows a logical naming convention similar to other programming languages like Java and C++, that also use names ending in "Error" or "Exception".

Example: ZeroDivisionError

In the following example, we are dividing a number by zero, which causes Python to raise a ZeroDivisionError -

try:
   result = 10 / 0
except ZeroDivisionError as e:
   print("Caught an error:", e)

We get the following output -

Caught an error: division by zero

Example: NameError

In this example, we try to use a variable that hasn't been defined. Python raises a NameError -

try:
   print(unknown_variable)
except NameError as e:
   print("Caught an error:", e)

The output is -

Caught an error: name 'unknown_variable' is not defined

Consistency in the Python Standard Library

The Python standard library includes many exceptions that follow this naming convention. This consistency helps you to remember and anticipate exception names easily.

Example: TypeError

In this example, we try to add a number and a string, which results in a TypeError -

try:
   result = 5 + "five"
except TypeError as e:
   print("Caught an error:", e)

The output is -

Caught an error: unsupported operand type(s) for +: 'int' and 'str'