How to work with date format columns in python polars dataframe?

Question

I have an excel spreadsheet(.xlsx) with a date of birth column as below.

On loading it using the below syntax:

pl.read_excel(r'C:\datos\test.xlsx',read_csv_options={'parse_dates':False})

the date of births are changing into two digit year format as below.

How to avoid this ? I would require the date format as the source format i.e four digit year MM/DD/YYYY.

Answer 1

One way is to parse the string dates and transform to date type:

df = pl.read_excel(r'C:\datos\test.xlsx',read_csv_options={'parse_dates':False})

df = df.with_column(pl.col('date_of_birth').str.strptime(pl.Date, fmt='%m-%d-%y').cast(pl.Datetime))

print(df)
┌─────────────────────┐
│ date_of_birth       │
│ -------------       │
│ datetime[μs]        │
╞═════════════════════╡
│ 2002-04-10 00:00:00 │
├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
│ 1997-02-09 00:00:00 │
└─────────────────────┘

Answer 2

Assuming your dataframe has loaded your date column as a string, I would first try

import pandas as pd
df['date_col'] = pd.to_datetime(df['date_col'],dayfirst=True, format='%m/%d/%Y')  

where df is your dataframe and 'date_col' is the column name of your date column.