timestamp column is written as date column

[romanovacca]

Are you using Python or Rust?

Python

Describe your bug.

When I have a dataframe with a timestamp column such as : 2021-01-01 00:15:00 , where the column type is Date64,
if I then use the df.to_csv() function, the resulting csv file only shows 2021-01-01, without the time.

What are the steps to reproduce the behavior?

df = pl.DataFrame(
        {
            "timestamp": ["2021-01-01 01:00:00","2021-01-01 02:00:00","2021-01-01 03:00:00"],
            "open": [100] * 3,
            "close": [110] * 3,
            "high": [120] * 3,
            "low": [99] * 3,
        }
    )
df["timestamp"] = df['timestamp'].str.strptime(pl.datatypes.Date64, "%Y-%m-%d %H:%M:%S")
df.to_csv("testing.csv")

What is the expected behavior?

I woudl expect it to be written with the time included.

[ritchie46]

jorgecarleitao/arrow2#453