Errors & debugging
Handle failures gracefully, raise helpful errors, and debug with confidence.
How to handle ZeroDivisionError in Python
Wrap a division operation in try/except to return None or a friendly message instead of crashing when dividing by zero.
def safe_divide(a, b):
"""Return a/b if possible, else None when dividing by zero."""
try:
return a / b
except ZeroDivisionError:
return None
def safe_divide_with_message(a, b):
"""Return a how-to message on divide-by-zero error."""
try:
return a / b
except ZeroDivisio…How to parse a traceback to get the last frame in Python
Extracts the innermost frame's file, line, and function name from a Python traceback object.
import sys
import traceback
def parse_traceback_last_frame(exc_info):
"""Return the file, line, and function of the last (innermost) frame."""
_, _, tb = exc_info
last_tb = tb
while last_tb.tb_next is not None:
last_tb = last_tb.tb_next
filename = last_tb.tb_frame.f_code.co_filename
l…Implement a Context Manager That Suppresses Exceptions in Python
Shows how to write a custom context manager that catches specified exceptions and optionally re-raises others, plus the stdlib contextlib.suppress alternative.
import contextlib
class SuppressExceptions:
def __init__(self, *exceptions):
self.exceptions = exceptions
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
if exc_type is None:
return False
if not self.exceptions or exc_type in se…Map Exception Type to HTTP Status Code in Python
Maps Python exception types to appropriate HTTP status codes using a dictionary lookup for consistent API error handling.
EXCEPTION_STATUS_MAP = {
ValueError: 400,
KeyError: 400,
TypeError: 400,
PermissionError: 403,
FileNotFoundError: 404,
AttributeError: 404,
TimeoutError: 408,
NotImplementedError: 501,
ConnectionError: 503,
}
def status_code_for(exception_type):
try:
return EXCEPTION_S…Retry an Operation on ConnectionError in Python
Retries an unreliable operation a fixed number of times when it raises a transient ConnectionError, with a small delay between attempts.
import time
import random
def unreliable_operation():
"""Simulates an operation that throws ConnectionError occasionally."""
if random.random() < 0.6:
raise ConnectionError("Transient network failure")
return "Operation succeeded"
def retry_operation(attempts=4, delay=0.2):
"""Retries the o…Try Except ValueError in Python: Handle Conversion Errors
Catch ValueError exceptions when converting strings to integers or performing arithmetic, returning None on failure instead of crashing.
def convert_to_int(value):
try:
return int(value)
except ValueError as error:
print(f"Conversion failed: {error}")
print(f"Problem value was: {repr(value)}")
return None
def divide_numbers(numerator, denominator):
try:
result = numerator / denominator
retur…Validate try except ValueError handler for beginners — errors debugging
Learn how to validate user input and handle division errors safely using try/except with ValueError and ZeroDivisionError in Python.
def divide_numbers(a, b):
"""Divide two numbers, catching division by zero and value errors."""
try:
result = a / b
except ZeroDivisionError:
print("Error: Cannot divide by zero!")
return None
except TypeError:
print("Error: Both arguments must be numbers!")
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Errors & debugging — Python code examples
What you will find here
This page collects errors & debugging snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.
Samples vs tutorials and challenges
Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.