Perl or Python: Convert date from dd/mm/yyyy to yy

Question

I have lots of dates in a column in a CSV file that I need to convert from dd/mm/yyyy to yyyy-mm-dd format. For example 17/01/2010 should be converted to 2010-01-17.

How can I do this in Perl or Python?

Answer 1

>>> from datetime import datetime
>>> datetime.strptime('02/11/2010', '%d/%m/%Y').strftime('%Y-%m-%d')
'2010-11-02'

or more hackish way (that doesn't check for validity of values):

>>> '-'.join('02/11/2010'.split('/')[::-1])
'2010-11-02'
>>> '-'.join(reversed('02/11/2010'.split('/')))
'2010-11-02'

Answer 2

Use Time::Piece (in core since 5.9.5), very similar to the Python solution accepted, as it provides the strptime and strftime functions:

use Time::Piece;
my $dt_str = Time::Piece->strptime('13/10/1979', '%d/%m/%Y')->strftime('%Y-%m-%d');

or

$ perl -MTime::Piece
print Time::Piece->strptime('13/10/1979', '%d/%m/%Y')->strftime('%Y-%m-%d');
1979-10-13
$