Smart Loop List Creation in Python for Django Choice fields

Question

So. The following isn't very 'smart' ;)

MONTHS = (
    ('Jan', 'Jan'),
    ('Feb', 'Feb'),
    ('Mar', 'Mar'),
    ('Apr', 'Apr'),
    ('May', 'May'),
    ('Jun', 'Jun'),
    ('Jul', 'Jul'),
    ('Aug', 'Aug'),
    ('Sep', 'Sep'),
    ('Oct', 'Oct'),
    ('Nov', 'Nov'),
    ('Dec', 'Dec'),
)

YEARS = (
    ('1995', '1995'),
    ('1996', '1996'),
    ('1997', '1997'),
    ('1998', '1998'),
    ('1999', '1999'),
    ('2000', '2000'),
    ('2001', '2001'),
    ('2002', '2002'),
    ('2003', '2003'),
    ('2004', '2004'),
    ('2005', '2005'),
    ('2006', '2006'),
    ('2007', '2007'),
    ('2008', '2008'),
    ('2009', '2009'),
    ('2010', '2010'),
)

I'm newer to python, and would love to produce stuff like this 'pythonically'.

Such as,

• a list of year tuples from 1995 to current year.
• a list of the abbreviated months of the year

Thanks Stackers'

Answer 1

In [17]: from datetime import datetime

In [18]: tuple((str(n), str(n)) for n in range(1995, datetime.now().year + 1))
Out[18]:
(('1995', '1995'),
 ('1996', '1996'),
 ('1997', '1997'),
 ('1998', '1998'),
 ('1999', '1999'),
 ('2000', '2000'),
 ('2001', '2001'),
 ('2002', '2002'),
 ('2003', '2003'),
 ('2004', '2004'),
 ('2005', '2005'),
 ('2006', '2006'),
 ('2007', '2007'),
 ('2008', '2008'),
 ('2009', '2009'),
 ('2010', '2010'))

In [19]: import calendar

In [20]: tuple((m, m) for m in calendar.month_abbr[1:])
Out[20]:
(('Jan', 'Jan'),
 ('Feb', 'Feb'),
 ('Mar', 'Mar'),
 ('Apr', 'Apr'),
 ('May', 'May'),
 ('Jun', 'Jun'),
 ('Jul', 'Jul'),
 ('Aug', 'Aug'),
 ('Sep', 'Sep'),
 ('Oct', 'Oct'),
 ('Nov', 'Nov'),
 ('Dec', 'Dec'))

Answer 2

Try using zip() to make a list of two-tuples.

MONTHS = ('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec')
somemonth = models.TextField(max_length=3, choices=zip(MONTHS,MONTHS))

choices will be set to [('Jan', 'Jan'), ('Feb', 'Feb'), ...].

---

In response to the comments on this answer, the "tuple" list comprehension version would be:

tuple((m, m) for m in MONTHS)

Versus the zip version:

tuple(zip(MONTHS, MONTHS))

But strictly speaking, Django doesn't need a tuple of choices, so:

zip(MONTHS, MONTHS)