[concept]OOP & Tooling
Logging & Debugging
# theory
print debugging works until it doesn't. logging gives you levels
(DEBUG, INFO, WARNING, ERROR) and you can send the output anywhere.
import logging, io
buf = io.StringIO()
handler = logging.StreamHandler(buf)
logger = logging.getLogger("demo")
logger.setLevel(logging.INFO)
logger.addHandler(handler)
logger.info("app started")
print(buf.getvalue().strip())For debugging an exception, do not let it crash silently. Catch the specific error and handle it:
try:
x = 1 / 0
except ZeroDivisionError:
print("caught: division by zero")Reading a traceback: start at the bottom. The last line is the error type and message. The lines above it are the call stack, newest last.
# examples [2]
# example 01 · logging to a buffer you can inspect
Attach a StreamHandler over StringIO and read it back
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# example 02 · catch the specific exception
Handle the error you expect, let the rest surface
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# challenges [2]
# challenge 01/02todo
Create a logger named 'demo' at INFO level with a StreamHandler writing to an io.StringIO buffer. Log the info message 'app started', then print the buffer's contents stripped.
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# challenge 02/02todo
Wrap code that computes 1 / 0 in a try/except that catches ZeroDivisionError and prints exactly: caught: division by zero
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