errors

python has man differnt error messges

exceptions

errors are sometimes called exceptions

exception hierarchy

https://docs.python.org/3/library/exceptions.html#exception-hierarchy

error types

https://www.w3schools.com/python/python_ref_exceptions.asp

typical error types

TypeError: using the wrong data type

ValueError: a value is not in the acceptable range

a traceback is an error report that helps fixing the code

a traceback can go back into the package's source code

raise

raise gives a specific error message

produces an error message, and code will stop

example code

def my_function(attribute):

    if type(attribute) == str:

      print(attribute)

    else:

      raise TypeError("My error message.") #an error will appear as 'TypeError: My error message.'

try except

try checks for errors inside a function

except gives out the error message

produces an error message, but subseqent code will run

syntax examples

def my_function(attribute):

    try:

      output = sum(attribute) / len(attribute)

      return output

    except:

      print("My error message.")

try:

   result = entry * 1.5

except:

   raise My_Exception("my description")

else:

    print(result)

finally:

    print("my suggestion")

pass

try:

   result = var_1 / var_2

except:

    pass

else:

    print(result)