Get unique values from a list in python [duplicate

Question

This question already has an answer here:

• Removing duplicates in lists 43 answers

I want to get the unique values from the following list:

[u'nowplaying', u'PBS', u'PBS', u'nowplaying', u'job', u'debate', u'thenandnow']

The output which I require is:

[u'nowplaying', u'PBS', u'job', u'debate', u'thenandnow']

This code works:

output = []
for x in trends:
    if x not in output:
        output.append(x)
print output

is there a better solution I should use?

Answer 1

Getting unique elements from List

mylist = [1,2,3,4,5,6,6,7,7,8,8,9,9,10]

Using Simple Logic from Sets - Sets are unique list of items

mylist=list(set(mylist))

In [0]: mylist
Out[0]: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Using Simple Logic

newList=[]
for i in mylist:
    if i not in newList:
        newList.append(i)

In [0]: mylist
Out[0]: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Using pop method ->pop removes the last or indexed item and displays that to user. video

k=0
while k < len(mylist):
    if mylist[k] in mylist[k+1:]:
        mylist.pop(mylist[k])
    else:
        k=k+1

In [0]: mylist
Out[0]: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Using Numpy

import numpy as np
np.unique(mylist)

In [0]: mylist
Out[0]: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Reference

Answer 2

To be consistent with the type I would use:

mylist = list(set(mylist))

Answer 3

def setlist(lst=[]):
   return list(set(lst))

Answer 4

The example you provided does not correspond to lists in Python. It resembles a nested dict, which is probably not what you intended.

A Python list:

a = ['a', 'b', 'c', 'd', 'b']

To get unique items, just transform it into a set (which you can transform back again into a list if required):

b = set(a)
print b
>>> set(['a', 'b', 'c', 'd'])

Answer 5

use set to de-duplicate a list, return as list

def get_unique_list(lst):
        if isinstance(lst,list):
            return list(set(lst))

Answer 6

from collections import OrderedDict


seq = [u'nowplaying', u'PBS', u'PBS', u'nowplaying', u'job', u'debate', u'thenandnow']

# Unordered (hashable items)
list(set(seq))
# Out: ['thenandnow', 'PBS', 'debate', 'job', 'nowplaying']

# Order-preserving
list(OrderedDict.fromkeys(seq))
# Out: ['nowplaying', 'PBS', 'job', 'debate', 'thenandnow']

Alternatively in Python 3.6+:

# Order-preserving
list(dict.fromkeys(seq))
# Out: ['nowplaying', 'PBS', 'job', 'debate', 'thenandnow']