CODEWITHSUNDEEP
python-3.xdatetime
체라치에
체라치에

Reputation: 177

Correct typos in date with python3

If someone inserts a string '2021-11-31' that doesn't exist as a date. How to correct the date like '2021-11-30'(last day of month) or '2021-12-01'(first day) with python?

The input date can be '2021-02-34' or '2021-12-35' or many wrong input.. and I want to make it a last day of month or a first day of next month.

The point is

  1. The program should know that the date is wrong or correct
  2. and then correct the date

Thank you!

Upvotes: 0

Views: 157

Answers (1)

qkzk
qkzk

Reputation: 297

As mentioned by Yunnosch in previous comments, you can't be sure the date is "correct".

I guess you're assuming the date format to be YYYY-MM-DD and want to constrain DD to be within 1-31 (or 1-28, 1-29, 1-30 depending on the month).

Here is a simple function that does this :

import calendar


def rectify_day(dt: str) -> str:
    """
    Rectify the date and month of a date.
    If the day part is greater than the last day of this month,
    it will constrain the day to be the last day of month.
    """
    year_s, month_s, day_s = dt.split("-")   # split the elements of the date
    year = int(year_s)                       # convert them to integers
    month = int(month_s)
    day = int(day_s)
    last_day_of_month = calendar.monthrange(year, month)[1] # get the last day of this month
    day = min(day, last_day_of_month)        # constrain the day to max possible value

    return f"{year}-{month:>02d}-{day:>02d}" # returns a formatted string

Use it like that :

>>> rectify_day("2021-01-32")
'2021-01-31'
>>> rectify_day("2021-02-29")
'2021-02-28'
>>> rectify_day("2021-01-10")
'2021-01-10'
>>> rectify_day("2021-12-12")
'2021-12-12'

Upvotes: 2

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