How can I remove duplicate words in a string with Python?

Question

Following example:

string1 = "calvin klein design dress calvin klein"

How can I remove the second two duplicates "calvin" and "klein"?

The result should look like

string2 = "calvin klein design dress"

only the second duplicates should be removed and the sequence of the words should not be changed!

Answer 1

def unique_list(l):
    ulist = []
    [ulist.append(x) for x in l if x not in ulist]
    return ulist

a="calvin klein design dress calvin klein"
a=' '.join(unique_list(a.split()))

Answer 2

string1 = "calvin klein design dress calvin klein"
words = string1.split()
print (" ".join(sorted(set(words), key=words.index)))

This sorts the set of all the (unique) words in your string by the word's index in the original list of words.

Answer 3

In Python 2.7+, you could use collections.OrderedDict for this:

from collections import OrderedDict
s = "calvin klein design dress calvin klein"
print ' '.join(OrderedDict((w,w) for w in s.split()).keys())

Answer 4

Cut and paste from the itertools recipes

from itertools import ifilterfalse

def unique_everseen(iterable, key=None):
    "List unique elements, preserving order. Remember all elements ever seen."
    # unique_everseen('AAAABBBCCDAABBB') --> A B C D
    # unique_everseen('ABBCcAD', str.lower) --> A B C D
    seen = set()
    seen_add = seen.add
    if key is None:
        for element in ifilterfalse(seen.__contains__, iterable):
            seen_add(element)
            yield element
    else:
        for element in iterable:
            k = key(element)
            if k not in seen:
                seen_add(k)
                yield element

I really wish they could go ahead and make a module out of those recipes soon. I'd very much like to be able to do from itertools_recipes import unique_everseen instead of using cut-and-paste every time I need something.

Use like this:

def unique_words(string, ignore_case=False):
    key = None
    if ignore_case:
        key = str.lower
    return " ".join(unique_everseen(string.split(), key=key))

string2 = unique_words(string1)

Answer 5

string = 'calvin klein design dress calvin klein'

def uniquify(string):
    output = []
    seen = set()
    for word in string.split():
        if word not in seen:
            output.append(word)
            seen.add(word)
    return ' '.join(output)

print uniquify(string)

Answer 6

You can use a set to keep track of already processed words.

words = set()
result = ''
for word in string1.split():
    if word not in words:
        result = result + word + ' '
        words.add(word)
print result

Answer 7

Several answers are pretty close to this but haven't quite ended up where I did:

def uniques( your_string ):    
    seen = set()
    return ' '.join( seen.add(i) or i for i in your_string.split() if i not in seen )

Of course, if you want it a tiny bit cleaner or faster, we can refactor a bit:

def uniques( your_string ):    
    words = your_string.split()

    seen = set()
    seen_add = seen.add

    def add(x):
        seen_add(x)  
        return x

    return ' '.join( add(i) for i in words if i not in seen )

I think the second version is about as performant as you can get in a small amount of code. (More code could be used to do all the work in a single scan across the input string but for most workloads, this should be sufficient.)

Answer 8

11 and 2 work perfectly:

    s="the sky is blue very blue"
    s=s.lower()
    slist = s.split()
    print " ".join(sorted(set(slist), key=slist.index))

and 2

    s="the sky is blue very blue"
    s=s.lower()
    slist = s.split()
    print " ".join(sorted(set(slist), key=slist.index))

Answer 9

Question: Remove the duplicates in a string

 from _collections import OrderedDict

    a = "Gina Gini Gini Protijayi"

    aa = OrderedDict().fromkeys(a.split())
    print(' '.join(aa))
   # output => Gina Gini Protijayi

Answer 10

You can remove duplicate or repeated words from a text file or string using following codes -

from collections import Counter
for lines in all_words:

    line=''.join(lines.lower())
    new_data1=' '.join(lemmatize_sentence(line))
    new_data2 = word_tokenize(new_data1)
    new_data3=nltk.pos_tag(new_data2)

    # below code is for removal of repeated words

    for i in range(0, len(new_data3)):
        new_data3[i] = "".join(new_data3[i])
    UniqW = Counter(new_data3)
    new_data5 = " ".join(UniqW.keys())
    print (new_data5)


    new_data.append(new_data5)


print (new_data)

P.S. -Do identations as per required. Hope this helps!!!

Answer 11

You can do that simply by getting the set associated to the string, which is a mathematical object containing no repeated elements by definition. It suffices to join the words in the set back into a string:

def remove_duplicate_words(string):
    return ' '.join(set(string.split()))

Answer 12

string2 = ' '.join(set(string1.split()))

Explanation:

.split() - it is a method to split string to list (without params it split by spaces)
set() - it is type of unordered collections that exclude dublicates
'separator'.join(list) - mean that you want to join list from params to string with 'separator' between elements