54

Let's say I have a string: "10/12/13" and "10/15/13", how can I convert them into date objects so that I can compare the dates? For example to see which date is before or after.

Sid K.
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7 Answers7

64

Use datetime.datetime.strptime:

>>> from datetime import datetime as dt
>>> a = dt.strptime("10/12/13", "%m/%d/%y")
>>> b = dt.strptime("10/15/13", "%m/%d/%y")
>>> a > b
False
>>> a < b
True
>>>
  • for some reason %y (lower case y) gave me "Unconverted data remains " error, while %Y (upper case Y) worked. Why? – LazerSharks Nov 06 '14 at 22:27
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    @Gnuey - The datetime format strings are case-sensitive. `%Y` is not the same as `%y`. `%Y` tells Python to match a 4-digit year such as `2014`. `%y` however matches a 2-digit year such as `14` for the year `2014`. You must be trying to match a 4-digit year with the 2-digit `%y` specifier. Here is a reference on the available format specifiers: https://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior –  Nov 06 '14 at 22:34
  • Ahh I see. Didn't catch that very valuable detail of "!4"vs"2014". Thank you for the answer and many thanks for the reference! – LazerSharks Nov 06 '14 at 22:39
16

If you like to use the dateutil and its parser:

from dateutil.parser import parse

date1 = parse('10/12/13')
date2 = parse('10/15/13')

print date1 - date2
print date2 > date2
gongzhitaao
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14

Here's one solution using datetime.datetime.strptime:

>>> date1 = datetime.datetime.strptime('10/12/13', '%m/%d/%y')
>>> date2 = datetime.datetime.strptime('10/15/13', '%m/%d/%y')
>>> date1 < date2
True
>>> date1 > date2
False
aIKid
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  • for some reason %y (lower case y) gave me "Unconverted data remains " error, while %Y (upper case Y) worked. Why? – LazerSharks Nov 06 '14 at 22:26
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    `%y` works with year without centuries - as a zero padded number (01, 02, 03.. and so on). While `%Y`works with year with century (decimal) number: (1999, 1979). What's your data? – aIKid Dec 11 '14 at 02:57
4

Use datetime.datetime.strptime.

from datetime import datetime

a = datetime.strptime('10/12/13', '%m/%d/%y')
b = datetime.strptime('10/15/13', '%m/%d/%y')

print 'a' if a > b else 'b' if b > a else 'tie'
Paul Draper
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3

I know this post is 7 years old, but wanted to say that you can compare two date strings without converting them to dates

>>> "10/12/13" > "10/15/13"
False
>>> "10/12/13" < "10/15/13"
True
>>> "10/12/13" == "10/15/13"
False

If there is anything wrong with this approach I would love for someone to tell me.

STIKO
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    Please refer to this answer for why this is a bad way to compare date strings. https://stackoverflow.com/a/31350422/4589310 – skyfail Mar 18 '21 at 19:40
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    A counterexample: `'10/15/13' > '10/12/14'` but `October 15, 2013` was before `October 12, 2014`. – Jeyekomon Dec 06 '21 at 13:33
0
import datetime

d1="10/12/13"
d2="10/15/13"
date = d1.split('/')
d1=datetime.datetime(int(date[2]),int(date[1]),int(date[0])) 
date = d2.split('/')
d2=datetime.datetime(int(date[2]),int(date[1]),int(date[0]))
if d1 > d2 :
    ## Code
today = datetime.datetime.today()
if d1 > today :
    ## code
Jishnu Jayaprakash
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    Please add more details to your answer, maybe a brief explanation of what the code does would help. – Gangula Nov 08 '20 at 11:40
-1

The simplest way to accomplish this is using Pandas

import pandas as pd
d1=pd.to_datetime("10/12/13")
d2=pd.to_datetime("10/12/15")

d1>d2

>>False
Mohsin Asif
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