throw_err.py

#!/usr/bin/env python

# This script raises an error based on 
# user-supplied command line argument

import sys

def print_usage():
    """Print usage and exit"""
    sys.stderr.write("usage: python raise_err.py <error type>\n")
    sys.stderr.write("available errors: \n")
    sys.stderr.write("\tassertion, io, import, index\n")
    sys.stderr.write("\tkey, name, os, type, value,\n")
    sys.stderr.write("\tzerodivision\n")
    sys.exit()

# Check args
if len(sys.argv) != 2:
    print_usage()

error_type = sys.argv[1]

if error_type == "assertion":
#    raise AssertionError
    assert False
elif error_type == "io":
#    raise IOError
    open('non-existant_file')
elif error_type == "import":
#    raise ImportError
    import foobar
elif error_type == "index":
#    raise IndexError
    a = [0,3]
    print(a[3])
elif error_type == "key":
#    raise KeyError
    a = {}
    print(a['a'])
elif error_type == "name":
#    raise NameError
    print(os.error)
elif error_type == "os":
#    raise OSError
    import os
    os.chdir('not_dir')
elif error_type == "type":
#    raise TypeError
    print(3 + 'three')
elif error_type == "value":
#    raise ValueError
    print(int('Hello world'))
elif error_type == "zerodivision":
#    raise ZeroDivisionError
    print(3/0)
else:
    sys.stderr.write("Sorry, not able to throw a(n) ")
    sys.stderr.write(error_type + " error\n")
    print_usage()