Python Shorts 16: Getting an exception description in Micro Python
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This is useful if you want to find out how your otherwise perfect code has just fallen to pieces. One of the nice things about Python is that when a program fails you get a description of what happened and where:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "main.py", line 21, in <module>
NameError: name 'zanzibar' isn't definedHowever, if you catch the exception you need a way of displaying this useful information in the handler. This is how you do it:
try:
mgr.setup(mgr.settings)
except Exception as e:
print(f"[CLB] Manager {name} crashed during setup:")
sys.print_exception(e)The call of sys.print_exception takes in the exception object that was thrown and prints the terribly useful message. If you want to put the message into a string (perhaps so you can log it or send it somewhere) you can do this:
import io
import sys
try:
x=zanzibar
except Exception as e:
buf = io.StringIO()
sys.print_exception(e, buf)
trace = buf.getvalue()
print("bang")
print(trace)The code above will throw an exception (unless your program contains a variable called zanzibar). The exception is copied into the variable called trace which you can then do what you like with.
