Convert text file date into specific format

[jacklee26]

Do anyone know how to convert a text file date format to specific format.
For example i have a text file and the file is 2018/01/02, and i wants to convert in into 20180102.
In hoilday.txt have many date in this format( year/m/d), and i wants to change to ymd format.

import datetime as dt
with open('holiday.txt') as f, open('new.txt', 'w') as f_out:
    for line in f:
        line = line.strip()
	f_out.write(dt.strftime('%d%m%Y'))
	

[wavic]

If it is a text you do not need datetime module.
Read the dates and replace '/' with "".

>>> line = "2018/01/02"
>>> line.replace('/', '')
'20180102'

[jacklee26]

0K thanks a lots.
i figure it out.

[buran]

Just for completeness, let's show transformation using datetime.datetime , because it would be useful for more complicated formats/conversions

from datetime import datetime
d = "2018/01/02"
print(datetime.strftime(datetime.strptime(d, '%Y/%m/%d'), '%Y%m%d'))

[jacklee26]

Hi this is my code.
It work, but i have another question.
What if my file have date and some word like this
2018/01/02 XXXXX
2018/01/03 cccccc

How can I just changed the date.
If i remove the word it can be success, but if i put the word in it, i will run error.
It will occur "ValueError: unconverted data remains: xxxxx"
Is there a way to fix this.

import datetime as dt
from datetime import datetime
with open('holiday.txt') as f, open('new.txt', 'w') as f_out:
    for line in f:
        line = line.strip()
	#line =line.replace('/', '')
	#f_out.write('{}\n'.format(line))
	f_out.write(datetime.strftime(datetime.strptime(line, '%Y/%m/%d'), '%Y%m%d'))

thanks

[wavic]

Split the line. Get the first element, convert it to the desired format and put the line back together.

[jacklee26]

is there any example i can reference to?
thanks

[wavic]

>>> line = '2018/01/03 cccccc'
>>> date = line.split()[0].replace('/', '')
>>> date
'20180103'
>>> new_line = f'{date}{line[line.index(" "):]}'
>>> new_line
'20180103 cccccc'

For examaple. Or you can modify it to use datetime. Try with datetime because you are working with dates so you have to practise.

[jacklee26]

Thanks. I solve it
This is my code. Is there any comment with my code, or any suggestion.

import datetime as dt
from datetime import datetime
with open('holiday.txt') as f, open('new.txt', 'w') as f_out:
    for line in f:
        line = line.strip()
	#line =line.replace('/', '')
	#f_out.write('{}\n'.format(line))
	#f_out.write(datetime.strftime(datetime.strptime(line, '%Y/%m/%d'), '%Y%m%d'))
	line.rstrip().split('  ')
	line_1 = line.split()[0]
	line_2 = line.split()[1]
	newline =(datetime.strftime(datetime.strptime(line_1, '%Y/%m/%d'), '%Y%m%d'))
	#result = line_1 +" " +line_2
	#f_out.write(result)
	f_out.write(line_1 +" " +line_2+ '\n')

[buran]

I don't think this would work as expected.
You need lines 9-15 indented one level or you will get just the last line processed.
Also you don't need one of the imports (better keep the second one). There are other lines of code that yield nothing.
Finally you write the date again using line_1, not newline

from datetime import datetime
with open('holiday.txt') as f, open('new.txt', 'w') as f_out:
    for line in f:
        line_1, line_2 = line.rstrip().split('  ')
        new_line_1 =(datetime.strftime(datetime.strptime(line_1, '%Y/%m/%d'), '%Y%m%d'))
        f_out.write('{} {}\n'.format(new_line_1, line_2))