Reformat a list of dates from "/" to "-" (using python)-CodePudding

I have a list of dates.

['1/12/2022', '1/13/2022','1/17/2022']

How do I reformat them to look like this:

['2022-1-12', '2022-1-13','2022-1-17']

EDIT: My original post asked about the wrong format. I've corrected it because I meant for the the format to be "Year-Month-Day"

CodePudding user response：

I am assuming you are using Python... Please correct me if I am wrong. You can loop through the list of dates using a enumerated for-loop (enumerate(list) function lets you know the index of each value during the loop) with each date, use the .replace() method of str to replace '/' with '-' like this:

list_of_dates = ['1/12/2022', '1/13/2022','1/17/2022']
for i, date in enumerate(list_of_dates):
    list_of_dates[i] = date.replace('/', '-')

or use list comprehension like this (thank you @Eli Harold ):

list_of_dates = [date.replace('/', '-') for date in list_of_dates]

If you want to change the order of the numbers in the date string you can split them by the '/' or '-' into a new list and change the order if you want like this:

for i, date in enumerate(list_of_dates):
    month, day, year = date.split('-') # assuming you already changed it to dashes
    list_of_dates[i] = f'{day}-{month}-{year}'

CodePudding user response：

you can use strptime

from datetime import datetime

dates = []
for date_str in ['1/12/2022', '1/13/2022','1/17/2022']:
   date = datetime.strptime(date_str, '%m/%d/%Y')
   dates.append(date.strftime('%m-%d-%Y'))

CodePudding user response：

I opted to split the individual dates and then add in the "-" delimiter after the fact, but you could also replace those on iteration. Once your data has been transformed, I just pushed it into a new list of reformatted dates.

This may not result in the best performance for longer iterations, though.


dates = ['1/12/2022', '1/13/2022','1/17/2022']
newdates = []
    for x in range(0, len(dates)):
        split_date = dates[x].split('/')
        month = split_date[0]
        day = split_date[1]
        year = split_date[2]
        your_date = year  "-" month "-" day
        newdates.apppend(your_date)
        print(your_date)

And the output:

2022-1-12
2022-1-13
2022-1-17

CodePudding user response：

from datetime import datetime

dates = [datetime.strptime(x, "%-m/%-d/%Y") for x in list_of_dates]
new_dates = [x.strftime("%Y-%-m-%-d") for x in dates]

CodePudding user response：

dates = ['1/12/2022', '1/13/2022','1/17/2022']
dates = [x.replace('/', '-') for x in dates]