Question

I’m trying to parse a free form date string into a meaningful date. So far I’ve come up with this function:

"""Parse raw date string into YYYY-MM-DD"""
def __parseDate(self, rawDate):
    if len(rawDate) == 0:
        return u""
    if "{{Birth year and age|" in rawDate:
        rawDate = rawDate.replace("{{","").replace("}}","")
        year = rawDate.split("|")[1].strip()
        return year + "-01-01"
    elif "{{Birth date and age|" in rawDate:
        rawDate = rawDate.replace("{{","").replace("}}","")
        year = rawDate.split("|")[1].strip()
        month = rawDate.split("|")[2].strip()
        day = rawDate.split("|")[3].strip()
        if len(month) == 1:
            month = "0" + month
        if len(day) == 1:
            day = "0" + day
        return year + "-" + month + "-" + day
    elif "{{" in rawDate:
        self.__log(u"XXX Date parse error (unknown template): " + rawDate)
        return u"1770-01-01"
    elif re.match("([a-zA-Z]* [0-9][0-9]?, [0-9][0-9][0-9][0-9])", rawDate):
        match = re.findall("([a-zA-Z]* [0-9][0-9]?, [0-9][0-9][0-9][0-9])", rawDate)[0]
        parts = match.replace(",","").split(" ")
        year = parts[2].strip()
        month = parts[0].replace(".","").strip()
        day = parts[1].strip()
        tryAgain = False
        try:
            month = str(strptime(month,'%B').tm_mon)
        except:
            tryAgain = True
            pass
        try:
            if tryAgain:
                month = str(strptime(month,'%b').tm_mon)
        except:
            self.__log(u"XXX Date parse error: " + rawDate)
            return u"1770-01-01"
            pass

        if len(month) == 1:
            month = "0" + month
        if len(day) == 1:
            day = "0" + day
        return year + "-" + month + "-" + day
    elif re.match("[0-9][0-9][0-9][0-9]-[0-9][0-9]?-[0-9][0-9]?", rawDate):
        parts = rawDate.split("-")
        year = parts[0].strip()
        month = parts[1].strip()
        day = parts[2].strip()
        if len(month) == 1:
            month = "0" + month
        if len(day) == 1:
            day = "0" + day
        return year + "-" + month + "-" + day
    else:
        self.__log(u"XXX Date parse error: " + rawDate)
        return u"1770-01-01"

Am I on the right track or is there a better way to go?

Update By free form string I mean this is coming from a wiki page, specifically the person data template. The date fields in this template are free form in that a human has typed something in it. Typically this is a date in any number of formats, or it is itself another wiki template describing the date. Here are some examples of what could be in the field:

{{Birth year and age|1933}}
August 23, 1967
1990-01-29
23 August 1967
1999
a;lsdfhals;djkfh

Answer 1

Probably the ultimate is parsedatetime.

Another choice would be dateutil.