What is the inverse of date.toordinal() in python?

Question

In python, a dateobject can be converted in the proleptic Gregorian ordinal this way:

d=datetime.date(year=2010, month=3, day=1)
d.toordinal()

but what is the reverse operation?

Answer 1

The opposite is date.fromordinal

classmethod date.fromordinal(ordinal)

    Return the date corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1. ValueError is raised unless 1 <= ordinal <= date.max.toordinal(). For any date d, date.fromordinal(d.toordinal()) == d.

Answer 2

It's date.fromordial() as Jon wrote in the comments.

or datetime.fromordinal()

You can read more about it in the date= documentation

and for datetime

From the docs:

classmethod date.fromordinal(ordinal)

Return the date corresponding to the proleptic Gregorian ordinal, where January 1 of year 1 has ordinal 1. ValueError is raised unless 1 <= ordinal <= date.max.toordinal().

For any date d, date.fromordinal(d.toordinal()) == d.