将奇怪的日期格式转换为标准日期格式

Question

In Sweden we sometimes use a strange date format, for example New Year is the 31/12. If I have this format as a string ,which can be any date between 1/1 and 31/12, and if we assume that it is this year, how do I get into a standard date format using Python (format as 2012-01-01 and 2012-12-31) that can be sore in be stored as a date in a mySQL database.

Answer 1

Simply split the two values, map them to integers and update a datetime.date() instance:

import datetime
day, month = map(int, yourvalue.split('/'))
adate = datetime.date.today().replace(month=month, day=day)

By using datetime.date.today() we get the current year.

Demo:

>>> import datetime
>>> somevalue = '31/12'
>>> day, month = map(int, somevalue.split('/'))
>>> datetime.date.today().replace(month=month, day=day)
datetime.date(2012, 12, 31)
>>> someothervalue = '1/1'
>>> day, month = map(int, someothervalue.split('/'))
>>> datetime.date.today().replace(month=month, day=day)
datetime.date(2012, 1, 1)

Alternatively, you could use the datetime.strptime() method to parse these dates, but you'll have to manually correct the year afterwards (it'll use 1900 as the default if no year is being parsed):

adate = datetime.datetime.strptime(yourvalue, '%d/%m').date()
adate = adate.replace(year=datetime.date.today().year)

Answer 2

There is nothing strange about this format :)

You can use the datetime module:

import datetime
d = datetime.datetime.strptime('31/12', '%d/%m').date().replace(year=2012)
print d

>> datetime.date(2012, 12, 31)