[Python-Dev] dateutil

[Greg Ewing]

> >>> now.replace(month=2, day=30)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in ?
> ValueError: day is out of range for month
> >>>
> 
> This makes operations like "move to the end of the current month"
> non-trivial (not *hard*, just non-trivial).

If I were designing something like this, I think I would approach it
quite differently, and provide a bunch of separate functions or
methods that transform dates in specific ways. e.g.

  end_of_month(d)
  forward_months(n, d)

then to "go to the end of the month 3 months from now" would
be

  end_of_month(forward_months(3, d))

or, if you prefer a method-chaining style,

  d.forward_months(3).end_of_month()

Greg Ewing, Computer Science Dept, +--------------------------------------+
University of Canterbury,	   | A citizen of NewZealandCorp, a	  |
Christchurch, New Zealand	   | wholly-owned subsidiary of USA Inc.  |
greg at cosc.canterbury.ac.nz	   +--------------------------------------+