BufferError

BufferError is a built-in exception that is raised when an operation can’t be performed on a buffer due to the current state of the buffer. A buffer is a contiguous block of memory that stores data temporarily, often used for input/output (I/O) operations to improve performance.

This exception is quite rare. You’d typically encounter it in low-level programming, such as when working with C extensions or certain modules like io and array that deal with buffer interfaces.

BufferError Practical Use Cases

  • Handling buffer-related operations when working with low-level data processing
  • Managing buffer states in C extensions or Python modules that expose buffer interfaces
  • Ensuring buffer availability and size are appropriate for the intended operations

BufferError Examples

An example of when the exception appears:

Python 
>>> data = bytearray(b"Hello")
>>> view = memoryview(data)

>>> data.extend(b" World!")
Traceback (most recent call last):
  ...
BufferError: Existing exports of data: object cannot be re-sized

In this example, you try to extend a bytearray while a memoryview object accesses its data. This causes Python to raise a BufferError.

An example of how to handle the exception:

Python 
>>> data = bytearray(b"Hello")
>>> view = memoryview(data)

>>> try:
...     data.extend(b" World!")
... except BufferError:
...     print("Forbidden operation. Delete the memoryview first.")
...
Forbidden operation. Delete the memoryview first.
Python's Built-In Exceptions: A Walkthrough With Examples

Tutorial

Python's Built-in Exceptions: A Walkthrough With Examples

In this tutorial, you'll get to know some of the most commonly used built-in exceptions in Python. You'll learn when these exceptions can appear in your code and how to handle them. Finally, you'll learn how to raise some of these exceptions in your code.

intermediate python

For additional information on related topics, take a look at the following resources:

By Leodanis Pozo Ramos • Updated March 6, 2025 • Reviewed by Martin Breuss
Python’s Built-in Exceptions Share Feedback