from decimal import Decimal, InvalidOperation

def getInt(d, key, default):
	""" Helper for dict.get to return the default on error. """
	try:
		return int(d.get(key, default))
	except ValueError:
		return default

def getDecimal(d, key, default):
	""" Helper for dict.get to return the default on error or a Decimal
	with a precision of 2. """
	try:
		return Decimal("%.2f" % float(d.get(key, default)), 2)
	except InvalidOperation:
		return default
	except ValueError:
		return default

def getError(err, msg):
	""" Get an error, write a message on it an return it. """
	err.write("\n%s\n" % (msg,))
	return err