Syntax
Syntax error refers to the structure and the rules.
>>> (1 + 2) # correct
3
>>> 2) # incorrect
# SyntaxError: invalid syntax
Runtime
Runtime errors does not appear until after the program has started (also called exceptions).
>>> first = "Hello"
>>> second = "World"
>>> first + " " + secoend
# NameError: name 'secoend' is not defined
Semantic
Semantic errors will not generate errors but it will not do the right thing.
# Semantic error
#
# The program performs concatenation instead of addition
# The programmer failed to convert the inputs to integers
num1 = input('Enter number 1: ')
num2 = input('Enter number 2: ')
sum = num1 + num2
if sum != int(num1) + int(num2):
print("Sum = " + sum + " / Incorrect - Semantic error")
num1 = input('Enter number 1: ')
num2 = input('Enter number 2: ')
sum = int(num1) + int(num2)
print("Sum = " + str(sum) + " / Correct")
Except
Use try/except statements to catch errors.
# Errors can be handled with ...
# try and except statements.
def calc(number, divider):
try:
return number/divider
except ZeroDivisionError:
print('Error: Division by zero')
except:
print('Error: Invalid argument')
assert calc(10, 2) == 5
assert calc(10, 0) == None # pass
# Error: Division by zero
Last update: 303 days ago
