How to get synonyms from nltk WordNet Python

Question

WordNet is great, but I'm having a hard time getting synonyms in nltk. If you search similar to for the word 'small' like here, it shows all of the synonyms.

Basically I just need to know the following: wn.synsets('word')[i].option() Where option can be hypernyms and antonyms, but what is the option for getting synonyms?

Answer 1

Perhaps these are not synonyms in the proper terminology of wordnet. But I also want my function to return all similar words, like 'weeny', 'flyspeck' etc. You can see them for the word 'small' in the author link. I used these code:

from nltk.corpus import wordnet as wn

def get_all_synonyms(word):
    synonyms = []
    for ss in wn.synsets(word):
        synonyms.extend(ss.lemma_names())
        for sim in ss.similar_tos():
            synonyms_batch = sim.lemma_names()
            synonyms.extend(synonyms_batch)
    synonyms = set(synonyms)
    if word in synonyms:
        synonyms.remove(word)
    synonyms = [synonym.replace('_',' ') for synonym in synonyms]
    return synonyms

get_all_synonyms('small')

Answer 2

You might be interested in a Synset:

>>> wn.synsets('small')
[Synset('small.n.01'),
 Synset('small.n.02'),
 Synset('small.a.01'),
 Synset('minor.s.10'),
 Synset('little.s.03'),
 Synset('small.s.04'),
 Synset('humble.s.01'),
 Synset('little.s.07'),
 Synset('little.s.05'),
 Synset('small.s.08'),
 Synset('modest.s.02'),
 Synset('belittled.s.01'),
 Synset('small.r.01')]

That's the same list of top-level entries that the web interface gave you.

If you also want the "similar to" list, that's not the same thing as the synonyms. For that, you call similar_tos() on each Synset.

So, to show the same information as the website, start with something like this:

for ss in wn.synsets('small'):
    print(ss)
    for sim in ss.similar_tos():
        print('    {}'.format(sim))

Of course the website is also printing the part of speech (sim.pos), list of lemmas (sim.lemma_names), definition (sim.definition), and examples (sim.examples) for each synset at both levels. and it's grouping them by parts of speech, and it's added in links to other things that you can follow, and so forth. But that should be enough to get you started.

Answer 3

Here are some helper functions to make NLTK easier to use, and two examples of how those functions can be used.

def download_nltk_dependencies_if_needed():
    try:
        nltk.word_tokenize('foobar')
    except LookupError:
        nltk.download('punkt')
    try:
        nltk.pos_tag(nltk.word_tokenize('foobar'))
    except LookupError:
        nltk.download('averaged_perceptron_tagger')

def get_some_word_synonyms(word):
    word = word.lower()
    synonyms = []
    synsets = wordnet.synsets(word)
    if (len(synsets) == 0):
        return []
    synset = synsets[0]
    lemma_names = synset.lemma_names()
    for lemma_name in lemma_names:
        lemma_name = lemma_name.lower().replace('_', ' ')
        if (lemma_name != word and lemma_name not in synonyms):
            synonyms.append(lemma_name)
    return synonyms

def get_all_word_synonyms(word):
    word = word.lower()
    synonyms = []
    synsets = wordnet.synsets(word)
    if (len(synsets) == 0):
        return []
    for synset in synsets:
        lemma_names = synset.lemma_names()
        for lemma_name in lemma_names:
            lemma_name = lemma_name.lower().replace('_', ' ')
            if (lemma_name != word and lemma_name not in synonyms):
                synonyms.append(lemma_name)
    return synonyms

Example 1: get_some_word_synonyms

This approach tends to return the most relevant synonyms, but some words like "angry" won't return any synonyms.

download_nltk_dependencies_if_needed()

words = ['dog', 'fire', 'erupted', 'throw', 'sweet', 'center', 'said', 'angry', 'iPhone', 'ThisIsNotARealWorddd', 'awesome', 'amazing', 'jim dandy', 'change']

for word in words:
    print('Synonyms for {}:'.format(word))
    synonyms = get_some_word_synonyms(word)
    for synonym in synonyms:
        print("    {}".format(synonym))

Example 1 output:

Synonyms for dog:
    domestic dog
    canis familiaris
Synonyms for fire:
Synonyms for erupted:
    erupt
    break out
Synonyms for throw:
Synonyms for sweet:
    henry sweet
Synonyms for center:
    centre
    middle
    heart
    eye
Synonyms for said:
    state
    say
    tell
Synonyms for angry:
Synonyms for iPhone:
Synonyms for ThisIsNotARealWorddd:
Synonyms for awesome:
    amazing
    awe-inspiring
    awful
    awing
Synonyms for amazing:
    amaze
    astonish
    astound
Synonyms for jim dandy:
Synonyms for change:
    alteration
    modification

Example 2: get_all_word_synonyms

This approach will return all possible synonyms, but some may not be very relevant.

download_nltk_dependencies_if_needed()

words = ['dog', 'fire', 'erupted', 'throw', 'sweet', 'center', 'said', 'angry', 'iPhone', 'ThisIsNotARealWorddd', 'awesome', 'amazing', 'jim dandy', 'change']

for word in words:
    print('Synonyms for {}:'.format(word))
    synonyms = get_some_word_synonyms(word)
    for synonym in synonyms:
        print("    {}".format(synonym))

Example 2 output:

Synonyms for dog:
    domestic dog
    canis familiaris
    frump
    cad
    bounder
    blackguard
    hound
    heel
    frank
    frankfurter
    hotdog
    hot dog
    wiener
    wienerwurst
    weenie
    pawl
    detent
    click
    andiron
    firedog
    dog-iron
    chase
    chase after
    trail
    tail
    tag
    give chase
    go after
    track
Synonyms for fire:
    firing
    flame
    flaming
    ardor
    ardour
    fervor
    fervour
    fervency
    fervidness
    attack
    flak
    flack
    blast
    open fire
    discharge
    displace
    give notice
    can
    dismiss
    give the axe
    send away
    sack
    force out
    give the sack
    terminate
    go off
    arouse
    elicit
    enkindle
    kindle
    evoke
    raise
    provoke
    burn
    burn down
    fuel
Synonyms for erupted:
    erupt
    break out
    irrupt
    flare up
    flare
    break open
    burst out
    ignite
    catch fire
    take fire
    combust
    conflagrate
    come out
    break through
    push through
    belch
    extravasate
    break
    burst
    recrudesce
Synonyms for throw:
    stroke
    cam stroke
    shed
    cast
    cast off
    shake off
    throw off
    throw away
    drop
    thrust
    give
    flip
    switch
    project
    contrive
    bewilder
    bemuse
    discombobulate
    hurl
    hold
    have
    make
    confuse
    fox
    befuddle
    fuddle
    bedevil
    confound
Synonyms for sweet:
    henry sweet
    dessert
    afters
    confection
    sweetness
    sugariness
    angelic
    angelical
    cherubic
    seraphic
    dulcet
    honeyed
    mellifluous
    mellisonant
    gratifying
    odoriferous
    odorous
    perfumed
    scented
    sweet-scented
    sweet-smelling
    fresh
    unfermented
    sugared
    sweetened
    sweet-flavored
    sweetly
Synonyms for center:
    centre
    middle
    heart
    eye
    center field
    centerfield
    midpoint
    kernel
    substance
    core
    essence
    gist
    heart and soul
    inwardness
    marrow
    meat
    nub
    pith
    sum
    nitty-gritty
    center of attention
    centre of attention
    nerve center
    nerve centre
    snapper
    plaza
    mall
    shopping mall
    shopping center
    shopping centre
    focus on
    center on
    revolve around
    revolve about
    concentrate on
    concentrate
    focus
    pore
    rivet
    halfway
    midway
Synonyms for said:
    state
    say
    tell
    allege
    aver
    suppose
    read
    order
    enjoin
    pronounce
    articulate
    enounce
    sound out
    enunciate
    aforesaid
    aforementioned
Synonyms for angry:
    furious
    raging
    tempestuous
    wild
Synonyms for iPhone:
Synonyms for ThisIsNotARealWorddd:
Synonyms for awesome:
    amazing
    awe-inspiring
    awful
    awing
Synonyms for amazing:
    amaze
    astonish
    astound
    perplex
    vex
    stick
    get
    puzzle
    mystify
    baffle
    beat
    pose
    bewilder
    flummox
    stupefy
    nonplus
    gravel
    dumbfound
    astonishing
    awe-inspiring
    awesome
    awful
    awing
Synonyms for jim dandy:
Synonyms for change:
    alteration
    modification
    variety
    alter
    modify
    vary
    switch
    shift
    exchange
    commute
    convert
    interchange
    transfer
    deepen

Answer 4

I've code Thesaurus Lookup for Synonym recently, I used this function :

def find_synonyms(keyword) :

    synonyms = []
    for synset in wordnet.synsets(keyword):
        for lemma in synset.lemmas():
            synonyms.append(lemma.name())

    return str(synonyms)

But if you prefer to host your own Dictionary, you might interested with my project on offline synonym dictionary lookup on my github page :

https://github.com/syauqiex/offline_english_synonym_dictionary

Answer 5

Simplest program to print the synonyms of a given word

from nltk.corpus import wordnet

for syn in wordnet.synsets("good"):
    for name in syn.lemma_names():
        print(name)

Answer 6

This worked for me

wordnet.synsets('change')[0].hypernyms()[0].lemma_names()

Answer 7

You can use wordnet.synset and lemmas in order to get all the synonyms:

example :

from itertools import chain
from nltk.corpus import wordnet

synonyms = wordnet.synsets(text)
lemmas = set(chain.from_iterable([word.lemma_names() for word in synonyms]))

Demo:

>>> synonyms = wordnet.synsets('change')
>>> set(chain.from_iterable([word.lemma_names() for word in synonyms]))
set([u'interchange', u'convert', u'variety', u'vary', u'exchange', u'modify', u'alteration', u'switch', u'commute', u'shift', u'modification', u'deepen', u'transfer', u'alter', u'change'])

Answer 8

If you want the synonyms in the synset (aka the lemmas that make up the set), you can get them with lemma_names():

>>> for ss in wn.synsets('small'):
>>>     print(ss.name(), ss.lemma_names())

small.n.01 ['small']
small.n.02 ['small']
small.a.01 ['small', 'little']
minor.s.10 ['minor', 'modest', 'small', 'small-scale', 'pocket-size',  'pocket-sized']
little.s.03 ['little', 'small']
small.s.04 ['small']
humble.s.01 ['humble', 'low', 'lowly', 'modest', 'small']    
...