In Python, I often want to receive the date etc. as a character string and process it, but since I google it every time, I will summarize it for myself. In my case, it is processed by selecting character string → datetime → character string.

Premise

Receives the date as a string. For example, I think there are the following cases.

2014-10-16
2014/10/16 20:29:39

It's a story of what to do if you want these one day later.

String → datetime

First parse the string.

import datetime

#In case of 1
date1 = '2014-10-16'
d = datetime.datetime.strptime(date1, '%Y-%m-%d')

#In case of 2
date2 = '2014/10/16 20:29:39'
d = datetime.datetime.strptime(date2, '%Y/%m/%d %H:%M:%S')

This will convert it to datetime. Other formats can be supported by changing the above % Y-% m-% d.

datetime processing

Calculate datetime using timedelta. I want one day later, so

d += datetime.timedelta(days = 1)

If you do, you will get one day later. If you pull it without adding it, it will be one day ago, and if you change days to hours, you can control the time instead of the date.

datetime → string

Finally, return datetime to a string.

date_stringj = d.strftime('%Y-%m-%d')

This will make it a string in the specified format.

Summary

Below is a program that puts these together, receives the date as a character string, and adds one day.

`add_1day.py`


#!/usr/bin/python
import datetime

date_string_input = '2014-10-31'
date_format = '%Y-%m-%d'

#String → datetime
d = datetime.datetime.strptime(date_string_input, date_format)
#datetime processing
d += datetime.timedelta(days = 1)
#datetime → string
date_string_output = d.strftime(date_format)

print date_string_output

When executed, it will be as follows.

$ python time.py
2014-11-01

String date manipulation in Python