Convert textual representation of numbers (twenty two) into integers (22)

number_text_to_integer.py

def number_text_to_integer(self, text):

	parts = text.split(' ')

	accumulator = 0
	oper = 'sum'

	units = ['','one','two','three','four','five','six','seven','eight','nine']
	teens = ['','eleven','twelve','thirteen','fourteen','fifteen','sixteen', 'seventeen','eighteen','nineteen']
	tens = ['','ten','twenty','thirty','forty','fifty','sixty','seventy', 'eighty','ninety', 'hundred']
	thousands = ['','thousand','million','billion','trillion','quadrillion', 'quintillion','sextillion','septillion','octillion', 'nonillion','decillion','undecillion','duodecillion', 'tredecillion','quattuordecillion','sexdecillion', 'septendecillion','octodecillion','novemdecillion', 'vigintillion']

	number = []
	totals = []

	for part in parts:

	    oper = 'sum'
	    nr = 0

	    if part in units:
		nr = units.index(part)

	    if part in tens:
		nr = int("%d0" % tens.index(part))
		if part == 'hundred':
		    oper = 'times'

	    if part in teens:
		nr = int("1%d" % teens.index(part))

	    if part in thousands:
		nr = int(1000**thousands.index(part))
		oper = 'times'

	    if oper == 'sum':
		accumulator += nr
	    elif oper == 'times':
		if accumulator == 0: 
		    accumulator = 1
		accumulator *= nr
		totals.append(accumulator)
		accumulator = 0

	    number.append(nr)

	totals.append(accumulator)
	return sum(totals)

print number_text_to_integer('one')
print number_text_to_integer('four')
print number_text_to_integer('ten')
print number_text_to_integer('eleven')
print number_text_to_integer('twelve')
print number_text_to_integer('twenty')
print number_text_to_integer('twenty two')
print number_text_to_integer('two hundred')
print number_text_to_integer('four hundred twenty two')
print number_text_to_integer('four thousand twenty two')
print number_text_to_integer('four thousand three hundred ninety two')
print number_text_to_integer('ten million four thousand three hundred ninety two')
print number_text_to_integer('ninety billion ten million four thousand three hundred ninety two')