Lesson 11 of 13

Errors and try / except

When an error happens at runtime, Python stops the program. try and except let you handle it instead of crashing.

PYTHON

try:
    qty = int("ten")
except ValueError:
    print("Please enter a number")

typo (missing bracket or :)	SyntaxError
undefined name	NameError
wrong type for the operation	TypeError
unsuitable value	ValueError
list index out of range	IndexError
missing dictionary key	KeyError
division by zero	ZeroDivisionError

PYTHON

def safe_divide(a, b):
    try:
        return a / b
    except ZeroDivisionError:
        return None

print(safe_divide(10, 2))
print(safe_divide(10, 0))

PYTHON

prices = {"Laptop": 4800}
try:
    print(prices["Phone"])
except KeyError as e:
    print("Missing product:", e)
finally:
    print("Lookup finished")

Errors and try / except

Exercises