How do I sort this list in Python, if my date is in a String?

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Question :

How do I sort this list in Python, if my date is in a String?
[{'date': '2010-04-01', 'people': 1047, 'hits': 4522}, {'date': '2010-04-03', 'people': 617, 'hits': 2582}, {'date': '2010-04-02', 'people': 736, 'hits': 3277}]

Suppose I have this list. How do I sort by “date”, which is an item in the dictionary. But, “date” is a string…

Asked By: TIMEX

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Answer #1:

.sort(key=lambda x: datetime.datetime.strptime(x['date'], '%Y-%m-%d'))

Answer #2:

Fortunately, ISO format dates, which seems to be what you have here, sort perfectly well as strings! So you need nothing fancy:

import operator
yourlistofdicts.sort(key=operator.itemgetter('date'))
Answered By: Alex Martelli

Answer #3:

Satoru.Logic’s solution is clean and simple. But, per Alex’s post, you don’t need to manipulate the date string to get the sort order right…so lose the .split('-')

This code will suffice:

records.sort(key=lambda x:x['date'])
Answered By: damzam

Answer #4:

In python 2.6 you can use soerted w/operator.itemgetter.
Since date is YYYY-MM-DD it is sorted even though its a string cause its largest to smallest – i use that format all the time for this reason

>>> import operator
>>> l = [{'date': '2010-04-01','people': 1047, 'hits': 4522}, 
         {'date': '2010-04-03', 'people': 617, 'hits': 2582}, 
         {'date': '2010-04-02', 'people': 736, 'hits': 3277}]
>>> sorted( l, key = operator.itemgetter('date') )
[{'date': '2010-04-01', 'hits': 4522, 'people': 1047}, {'date': '2010-04-02', 'hits': 3277, 'people': 736}, {'date': '2010-04-03', 'hits': 2582, 'people': 617}]
Answered By: Rescommunes

Answer #5:

records = [
     {'date': '2010-04-01', 'people': 1047, 'hits': 4522}, 
     {'date': '2010-04-03', 'people': 617, 'hits': 2582}, 
     {'date': '2010-04-02', 'people': 736, 'hits': 3277}
     ]
records.sort(key=lambda x: x['date'].split('-'))
Answered By: satoru

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