CODEWITHSUNDEEP
pythonpython-3.x
Dheerendra
Dheerendra

Reputation: 1568

Find the occurrences of unique element in list in python

For finding occurrences of unique element in a list in python i used

import collections

a='77888'
b=list(collections.Counter(a).items())

but the b is sorted in order of occurences b=[('8',3),('7',2)]. But is want unsorted b. How can i achieve this?

Upvotes: 0

Views: 148

Answers (1)

jfs
jfs

Reputation: 414079

To find unique items in the list a:

from collections import Counter

unique_items = [item for item, count in Counter(a).items() if count == 1]

If input is sorted then you could use itertools.groupby():

from itertools import groupby

unique_items = [key for key, group in groupby(a) if len(list(group)) == 1]

If you want to get items and their frequencies in the same order as in the input, you could define OrderedCounter:

from collections import Counter, OrderedDict

class OrderedCounter(Counter, OrderedDict):
    pass

then:

>>> list(OrderedCounter('77888').items())
[('7', 2), ('8', 3)]
>>> list(OrderedCounter('88877').items())
[('8', 3), ('7', 2)]

Upvotes: 1

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