Pandas 'astype' with date (or datetime)

Question

This answer contains a very elegant way of setting all the types of your pandas columns in one line:

# convert column "a" to int64 dtype and "b" to complex type
df = df.astype({"a": int, "b": complex})

I am starting to think that that unfortunately has limited application and you will have to use various other methods of casting the column types sooner or later, over many lines. I tested 'category' and that worked, so it will take things which are actual python types like int or complex and then pandas terms in quotation marks like 'category'.

I have a column of dates which looks like this:

25.07.10
08.08.10
07.01.11

I had a look at this answer about casting date columns but none of them seem to fit into the elegant syntax above.

I tried:

from datetime import date
df = df.astype({"date": date})

but it gave an error:

TypeError: dtype '<class 'datetime.date'>' not understood

I also tried pd.Series.dt.date which also didn't work. Is it possible to cast all your columns including the date or datetime column in one line like this?

Answer 1

This has been answered in the comments where it was noted that the following works:

df.astype({'date': 'datetime64[ns]'})

In addition, you can set the dtype when reading in the data:

pd.read_csv('path/to/file.csv', parse_dates=['date'])