CODEWITHSUNDEEP
pythonpython-2.7
idealistikz
idealistikz

Reputation: 1267

What is the most efficient way to sort a list of dates in string format in Python?

Suppose I have a list of dates in the string format, 'YYYYMMDD.' How do I sort the list in regular and reverse order?

Upvotes: 1

Views: 574

Answers (3)

9000
9000

Reputation: 40884

Strings sort naturally. Use list.sort (in-place) or built-in sorted (copying).

Both accept a boolean parameter named reverse which defaults to False; set to True fr reverse order.

Upvotes: 3

Ned Batchelder
Ned Batchelder

Reputation: 375494

These are the two ways:

print sorted(my_list)
print sorted(my_list, reverse=True)

The whole reason people use dates in YYYYMMDD format is so that lexicographic (string) sorting will accomplish a date sort.

Upvotes: 7

John La Rooy
John La Rooy

Reputation: 304137

For that particular format, you can just sort them as strings

>>> sorted(['20100405','20121209','19990606'])
['19990606', '20100405', '20121209']
>>> sorted(['20100405','20121209','19990606'], reverse=True)
['20121209', '20100405', '19990606']

This works because in that format the digits are in the order of most significant to least significant

Upvotes: 11

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