Python - converting strings in an array to dates

Question

I have read an array of strings from a TXT file and saved it as an array (of over thousand values) using such a line:

dates = np.genfromtxt('filename.txt', delimiter=";", usecols=(0), dtype=None)

Next, I would like to convert strings into dates. I tried to use the line:

dates2 = dt.datetime.strptime([dates], '"%Y-%m-%d"').date()

however, I got an error:

TypeError: must be string, not list

I figured out that such a code works fine:

data1='"2010-02-28"'
data1_1 = dt.datetime.strptime(data1, '"%Y-%m-%d"').date()

How should I deal with the described problem?

DeepSpace · Accepted Answer · 2021-11-15T17:22:25.503

34

Note to future readers: Please do not edit this answer. '"%Y-%m-%d"' is not a mistake. OP's dates are surrounded by quotes.

dates is a list of strings. So if you want to create a list of dates from its elements:

dates_list = [dt.datetime.strptime(date, '"%Y-%m-%d"').date() for date in dates]

This line iterates over the strings in the dates list and using list comprehension to create a new list of dates.

edited Nov 15 '21 at 17:22

answered May 27 '15 at 16:16

DeepSpace

I'm using Python 3.7.3 and I needed to remove the double quotes in order for this to work for me. – Michael Szczepaniak Sep 11 '19 at 22:36
@MichaelSzczepaniak that's because your date strings are not surrounded with double-quotes like OP's. – DeepSpace Sep 12 '19 at 08:21
@DeepSpace OP stands for ? to make this work I had to remove double-quotes " – Anuj Gupta Oct 25 '19 at 18:57
1

@AnujGupta Original Poster, ie the quesion asker – DeepSpace Oct 25 '19 at 20:25
What does `dt` refer to in `dt.datetime`? Thanks – Confounded Mar 09 '20 at 14:32
2

@Confounded the `datetime` module, which is canonically imported as `import datetime as dt` – DeepSpace Mar 09 '20 at 14:33

score 1 · Answer 2 · edited Nov 15 '21 at 16:41

1

You can use split for faster result:

from datetime import datetime
today = datetime.now().strftime("%Y-%m-%d").split('-')

edited Nov 15 '21 at 16:41

Nimantha

answered Feb 16 '20 at 15:03

PouriaDiesel

2 Answers2