I don't know how to monkey patch this into the dt namespace but otherwise, here ya go

def replace(self, year=None, month=None, day=None):
    """Mimic the datetime replace method"""
    if year is None and month is None and day is None:
        raise ValueError("don't you want to replace something, specify a year, month, and/or day")
    if year is None:
        outyear=self.dt.year()
    else:
        outyear=year
    if month is None:
        outmonth=self.dt.month()
    else:
        outmonth=month
    if day is None:
        outday=self.dt.day()
    else:
        outday=day
    return pl.date(outyear, outmonth, outday)
pl.Expr.replace=replace

then you can do

df.select(
    col("my_date").replace(year=col("year"))
)

Thanks @deanm0000 . Yeah, I currently have my own monkeypatched methods but I felt it would be a good addition to the API.

FYI, when you post code in github, you can fence it with a language, e.g. ```python and you'll get syntax highlighting.

@MarcoGorelli does someone want to accept this feature request? I can work on it but I don't want to spend the time if it's not desired/will be rejected.

(FYI this is the original one :D)

sure, marking as 'accepted', feel free to ping me for review

i don't think anyone's actively working on it, are you interetsed in taking it?

EDIT: not sure why github is displaying this comment above @Andre-Medina 's below, even though my comment came after, my guess is that it's a DST-related but at GitHub 🤣 (today the clocks changed in the US, but not in the UK where I live)

was this issue still being worked on?

i don't think anyone's actively working on it, are you interetsed in taking it?

I wish I had the rust know how. I looked into this issue a few months back but my 0 rust experience held me back, especially with how technical the polars repo seems to be. Would love to learn one day :)

EDIT: not sure why github is displaying this comment above @Andre-Medina 's below, even though my comment came after, my guess is that it's a DST-related but at GitHub 🤣 (today the clocks changed in the US, but not in the UK where I live)

Haha wow that's very odd. For me it says your comment is slightly older. Love DST. thought everything would be UNIX timestamped tho?

I have an almost-working implementation, just need to find some time one of these days to finalize it.