python实现将英文单词表示的数字转换成阿拉伯数字的方法

import re
_known = {
 'zero': 0,
 'one': 1,
 'two': 2,
 'three': 3,
 'four': 4,
 'five': 5,
 'six': 6,
 'seven': 7,
 'eight': 8,
 'nine': 9,
 'ten': 10,
 'eleven': 11,
 'twelve': 12,
 'thirteen': 13,
 'fourteen': 14,
 'fifteen': 15,
 'sixteen': 16,
 'seventeen': 17,
 'eighteen': 18,
 'nineteen': 19,
 'twenty': 20,
 'thirty': 30,
 'forty': 40,
 'fifty': 50,
 'sixty': 60,
 'seventy': 70,
 'eighty': 80,
 'ninety': 90
 }
def spoken_word_to_number(n):
 """Assume n is a positive integer".
assert _positive_integer_number('nine hundred') == 900
assert spoken_word_to_number('one hundred') == 100
assert spoken_word_to_number('eleven') == 11
assert spoken_word_to_number('twenty two') == 22
assert spoken_word_to_number('thirty-two') == 32
assert spoken_word_to_number('forty two') == 42
assert spoken_word_to_number('two hundred thirty two') == 232
assert spoken_word_to_number('two thirty two') == 232
assert spoken_word_to_number('nineteen hundred eighty nine') == 1989
assert spoken_word_to_number('nineteen eighty nine') == 1989
assert spoken_word_to_number('one thousand nine hundred and eighty nine') == 1989
assert spoken_word_to_number('nine eighty') == 980
assert spoken_word_to_number('nine two') == 92 # wont be able to convert this one
assert spoken_word_to_number('nine thousand nine hundred') == 9900
assert spoken_word_to_number('one thousand nine hundred one') == 1901
"""
 n = n.lower().strip()
 if n in _known:
 return _known[n]
 else:
 inputWordArr = re.split('[ -]', n)
 assert len(inputWordArr) > 1 #all single words are known
 #Check the pathological case where hundred is at the end or thousand is at end
 if inputWordArr[-1] == 'hundred':
 inputWordArr.append('zero')
 inputWordArr.append('zero')
 if inputWordArr[-1] == 'thousand':
 inputWordArr.append('zero')
 inputWordArr.append('zero')
 inputWordArr.append('zero')
 if inputWordArr[0] == 'hundred':
 inputWordArr.insert(0, 'one')
 if inputWordArr[0] == 'thousand':
 inputWordArr.insert(0, 'one')
 inputWordArr = [word for word in inputWordArr if word not in ['and', 'minus', 'negative']]
 currentPosition = 'unit'
 prevPosition = None
 output = 0
 for word in reversed(inputWordArr):
 if currentPosition == 'unit':
 number = _known[word]
 output += number
 if number > 9:
 currentPosition = 'hundred'
 else:
 currentPosition = 'ten'
 elif currentPosition == 'ten':
 if word != 'hundred':
 number = _known[word]
 if number < 10:
 output += number*10
 else:
 output += number
 #else: nothing special
 currentPosition = 'hundred'
 elif currentPosition == 'hundred':
 if word not in [ 'hundred', 'thousand']:
 number = _known[word]
 output += number*100
 currentPosition = 'thousand'
 elif word == 'thousand':
 currentPosition = 'thousand'
 else:
 currentPosition = 'hundred'
 elif currentPosition == 'thousand':
 assert word != 'hundred'
 if word != 'thousand':
 number = _known[word]
 output += number*1000
 else:
 assert "Can't be here" == None
 return(output)