正则表达式，获取价格。 但是小数点或逗号

Question

I want to get the prices out of text using regex.

Small example: "This great product only for €1.000,59 today!"

I would like to get the price from the text as written above. This is my python regex so far:

re.findall(ur'([0-9,.]*)', text)

There is only a small problem. Some texts use commas (,) for splitting the decimals, others use dots (.) and some of them don't even have decimals or replaced the 00 decimals with a dash (-), like €59,-

So the ideal situation, to get all prices without any problem would be (in my opinion):

• If you check the numbers from right to left, is the 3rd character a dot or comma (cause every price does not contain more than 2 decimals)?
• Does it contain a dash (like €50,-)?

If both is NO: remove all dots and commas. If one of the two questions is YES: if the decimals are seperated by a dot (.), replace that dot with a comma, or if it's already a comma, just leave it like that. And remove the rest of the commas and dots.

Is that possible with regex?

Answer 1

Edit:

Sorry, I did not read the problem description carefully enough. I think to solve the problem, you need two regex patterns. First do a re.sub() then re.findall()

pattern = re.compile(r'(([.,]{1})(\d{1,3}|-))')  
s = "2,456,777.00  xxxxxxxxxxxxx 59,789,- xxxxxxxxxxxx 59,-  xxxxxxxxxx 1.000,59"

def subs(m):
    g0 = m.group(0)
    g3 = m.group(3)

    if g3 == '-':
        g3 = '00'
    if len(g0) == 4:
        return ',' + g0[1:4]
    else:
        return '.' + g3

c = re.findall(r'[\d.,-]+', re.sub(pattern, subs, s))
print c

>> ['2,456,777.00', '59,789.00', '59.00', '1,000.59']

A little cumbersome indeed. Hope someone can come up with a smarter one.