使用NLTK查找事物列表（例如河流列表）

Question

I would like to get lists of things, for example a list of names of rivers or a list of types of animals.

NLTK looks like it might be the thing for this, but I'm not sure how to do what I want. I'd like to have a function like:

get_list_of("river")

that would return something like

["amazon", "mississippi", "thames", ...]

Answer 1

I would suggest looking at NLTK wordnet API, see http://www.nltk.org/howto/wordnet.html .

But after doing some digging seems like Proper Nouns (ie names of river are not easy to track down in wordnet)

>>> from nltk.corpus import wordnet as wn
>>> wn.synsets('river')
[Synset('river.n.01')]
>>> wn.synset('river.n.01')
Synset('river.n.01')
>>> wn.synset('river.n.01').lemma_names
['river']
>>> wn.synsets('amazon')
[Synset('amazon.n.01'), Synset('amazon.n.02'), Synset('amazon.n.03'), Synset('amazon.n.04')]
>>> wn.synset('amazon.n.01').definition
'a large strong and aggressive woman'
>>> wn.synset('amazon.n.02').definition
'(Greek mythology) one of a nation of women warriors of Scythia (who burned off the right breast in order to use a bow and arrow more effectively)'
>>> wn.synset('amazon.n.03').definition
"a major South American river; arises in the Andes and flows eastward into the South Atlantic; the world's 2nd longest river (4000 miles)"
>>> wn.synset('amazon.n.04').definition
'mainly green tropical American parrots'

As a brute force way, look for "river" in a synsets' definitions, as such:

from itertools import chain
list(chain(*[i.lemma_names for i in wn.all_synsets() if "river" in i.definition]))

[out]:

['anaclinal', 'cataclinal', 'Acheronian', 'Acherontic', 'Stygian', 'hit-and-run', 'fluvial', 'riparian', 'Lao', 'debouch', 'rejuvenate', 'drive', 'ford', 'ascend', 'plant', 'drive', 'ford', 'fording', 'drive', 'driving', 'flood_control', 'conservancy', 'road_rage', 'Aegospotami', 'Aegospotamos', 'Yalu_River', 'three-spined_stickleback', 'Gasterosteus_aculeatus', 'ten-spined_stickleback', 'Gasterosteus_pungitius', 'placoderm', 'hellbender', 'mud_puppy', 'Cryptobranchus_alleganiensis', 'plains_spadefoot', 'Scaphiopus_bombifrons', 'mud_turtle', 'cooter', 'river_cooter', 'Pseudemys_concinna', 'spiny_softshell', 'Trionyx_spiniferus', 'smooth_softshell', 'Trionyx_muticus', 'teal', 'pintail', 'pin-tailed_duck', 'Anas_acuta', 'Ancylus', 'genus_Ancylus', 'freshwater_mussel', 'freshwater_clam', 'long-clawed_prawn', 'river_prawn', 'Palaemon_australis', 'Platanistidae', 'family_Platanistidae', 'hippopotamus', 'hippo', 'river_horse', 'Hippopotamus_amphibius', 'waterbuck', 'Australian_lungfish', 'Queensland_lungfish', 'Neoceratodus_forsteri', 'alewife', 'Alosa_pseudoharengus', 'Pomolobus_pseudoharengus', 'sockeye', 'sockeye_salmon', 'red_salmon', 'blueback_salmon', 'Oncorhynchus_nerka', 'brown_trout', 'salmon_trout', 'Salmo_trutta', 'Australian_arowana', 'Dawson_River_salmon', 'saratoga', 'spotted_barramundi', 'spotted_bonytongue', 'Scleropages_leichardti', 'Australian_bonytongue', 'northern_barramundi', 'Scleropages_jardinii', 'crappie', 'striped_bass', 'striper', 'Roccus_saxatilis', 'rockfish', 'bolti', 'Tilapia_nilotica', 'Chinese_paddlefish', 'Psephurus_gladis', 'air_bag', 'Augean_stables', 'barouche', 'bend', 'curve', 'boathouse', 'box', 'box_seat', 'brassie', 'bridge', 'span', 'bridle', 'brougham', 'buggy_whip', 'cab', 'car_mirror', 'coach', 'four-in-hand', 'coach-and-four', 'cockpit', 'death_seat', 'dredge', 'dredging_bucket', 'elbow', 'flat_tip_screwdriver', 'hansom', 'hansom_cab', 'keelboat', 'Lake_Volta', 'levee', 'levee', 'L-plate', 'machine_screw', 'outfall', 'Phillips_screwdriver', 'pull-in', 'pull-up', 'river_boat', 'showboat', 'skidpan', 'spiral_ratchet_screwdriver', 'ratchet_screwdriver', 'towpath', 'towing_path', 'truck_stop', 'willowware', 'willow-pattern', 'woodscrew', 'Copehan', 'Volgaic', 'horn', 'rip', 'riptide', 'tide_rip', 'crosscurrent', 'countercurrent', 'crappie', 'red_salmon', 'sockeye', 'sockeye_salmon', 'logjam', 'Teamsters_Union', 'car_pool', 'conservancy', 'headwater', 'river_basin', 'basin', 'watershed', 'drainage_basin', 'catchment_area', 'catchment_basin', 'drainage_area', 'confluence', 'meeting', 'Mammoth_Cave_National_Park', 'Zion_National_Park', 'watershed', 'water_parting', 'divide', 'Yangon', 'Rangoon', "N'Djamena", 'Ndjamena', 'Fort-Lamy', 'capital_of_Chad', 'Kinshasa', 'Leopoldville', 'Saxony', 'Sachsen', 'Saxe', 'Cologne', 'Koln', 'Mannheim', 'Rhineland', 'Rheinland', 'Ruhr', 'Ruhr_Valley', 'West_Bank', 'Pennines', 'Pennine_Chain', 'Ottawa', 'Canadian_capital', 'capital_of_Canada', 'Antwerpen', 'Antwerp', 'Anvers', 'Orleans', 'Rhone-Alpes', 'Friesland', 'Timbuktu', 'Bydgoszcz', 'Bromberg', 'Novosibirsk', 'Tbilisi', 'Tiflis', 'capital_of_Georgia', 'Toledo', 'Selma', 'Denver', 'Mile-High_City', 'capital_of_Colorado', 'Hartford', 'capital_of_Connecticut', 'Savannah', 'Topeka', 'capital_of_Kansas', 'Louisville', 'New_Orleans', 'Detroit', 'Motor_City', 'Motown', 'Minneapolis', 'Saint_Paul', 'St._Paul', 'capital_of_Minnesota', 'Jefferson_City', 'capital_of_Missouri', 'Saint_Louis', 'St._Louis', 'Gateway_to_the_West', 'Billings', 'Great_Falls', 'Omaha', 'Concord', 'capital_of_New_Hampshire', 'Manchester', 'Trenton', 'capital_of_New_Jersey', 'Albuquerque', 'New_Netherland', 'Albany', 'capital_of_New_York', 'Erie_Canal', 'New_York', 'New_York_City', 'Greater_New_York', 'West_Point', 'Niagara_Falls', 'Schenectady', 'Bismarck', 'capital_of_North_Dakota', 'Fargo', 'Cincinnati', 'Tulsa', 'Chester', 'Philadelphia', 'City_of_Brotherly_Love', 'Pierre', 'capital_of_South_Dakota', 'Mount_Vernon', 'Charleston', 'capital_of_West_Virginia', 'Huntington', 'Morgantown', 'Parkersburg', 'Wheeling', 'Casper', 'Ciudad_Bolivar', 'Aare', 'Aar', 'Aare_River', 'Acheron', 'River_Acheron', 'Adige', 'River_Adige', 'Aire', 'River_Aire', 'Aire_River', 'Alabama', 'Alabama_River', 'Allegheny', 'Allegheny_River', 'Amazon', 'Amazon_River', 'Amur', 'Amur_River', 'Heilong_Jiang', 'Heilong', 'Angara', 'Angara_River', 'Tunguska', 'Upper_Tunguska', 'Apalachicola', 'Apalachicola_River', 'Araguaia', 'Araguaia_River', 'Araguaya', 'Araguaya_River', 'Aras', 'Araxes', 'Arauca', 'Argun', 'Argun_River', 'Ergun_He', 'Arkansas', 'Arkansas_River', 'Arno', 'Arno_River', 'River_Arno', 'Avon', 'River_Avon', 'Upper_Avon', 'Upper_Avon_River', 'Avon', 'River_Avon', 'bar', 'Bighorn', 'Bighorn_River', 'Big_Sioux_River', 'billabong', 'bluff', 'body_of_water', 'water', 'bottomland', 'bottom', 'Brahmaputra', 'Brahmaputra_River', 'branch', 'Brazos', 'Brazos_River', 'brook', 'creek', 'Caloosahatchee', 'Caloosahatchee_River', 'Cam', 'River_Cam', 'Cam_River', 'Canadian', 'Canadian_River', 'canyon', 'canon', 'Cape_Fear_River', 'channel', 'Chao_Phraya', 'Charles', 'Charles_River', 'Chattahoochee', 'Chattahoochee_River', 'Cimarron', 'Cimarron_River', 'Clinch_River', 'Clyde', 'Cocytus', 'River_Cocytus', 'Colorado', 'Colorado_River', 'Colorado', 'Colorado_River', 'Columbia', 'Columbia_River', 'Congo', 'Congo_River', 'Zaire_River', 'Connecticut', 'Connecticut_River', 'Coosa', 'Coosa_River', 'Cumberland', 'Cumberland_River', 'dale', 'Danube', 'Danube_River', 'Danau', 'Darling', 'Darling_River', 'Delaware', 'Delaware_River', 'delta', 'Demerara', 'Detroit_River', 'distributary', 'Dnieper', 'Dnieper_River', 'Don', 'Don_River', 'Ebro', 'Ebro_River', 'Elbe', 'Elbe_River', 'Elizabeth_River', 'estuary', 'Euphrates', 'Euphrates_River', 'Flint', 'Flint_River', 'floodplain', 'flood_plain', 'Forth', 'Forth_River', 'Fox_River', 'Ganges', 'Ganges_River', 'Gan_Jiang', 'Kan_River', 'Garonne', 'Garonne_River', 'Gila', 'Gila_River', 'gorge', 'Grand_River', 'Green', 'Green_River', 'headstream', 'Housatonic', 'Housatonic_River', 'Huang_He', 'Hwang_Ho', 'Yellow_River', 'Hudson', 'Hudson_River', 'IJssel', 'IJssel_river', 'Illinois_River', 'Indigirka', 'Indigirka_River', 'Indus', 'Indus_River', 'Irrawaddy', 'Irrawaddy_River', 'Irtish', 'Irtish_River', 'Irtysh', 'Irtysh_River', 'Isere', 'Isere_River', 'James', 'James_River', 'James', 'James_River', 'Jordan', 'Jordan_River', 'Kansas', 'Kansas_River', 'Kaw_River', 'Kasai', 'Kasai_River', 'River_Kasai', 'Kissimmee', 'Kissimmee_River', 'Klamath', 'Klamath_River', 'Kura', 'Kura_River', 'Lake_Chad', 'Chad', 'Lehigh_River', 'Lena', 'Lena_River', 'Lethe', 'River_Lethe', 'liman', 'Limpopo', 'Crocodile_River', 'Little_Bighorn', 'Little_Bighorn_River', 'Little_Horn', 'Little_Missouri', 'Little_Missouri_River', 'Little_Sioux_River', 'Little_Wabash', 'Little_Wabash_River', 'Loire', 'Loire_River', 'Mackenzie', 'Mackenzie_River', 'Madeira', 'Madeira_River', 'Magdalena', 'Magdalena_River', 'meander', 'Mekong', 'Mekong_River', 'Merrimack', 'Merrimack_River', 'Meuse', 'Meuse_River', 'Milk', 'Milk_River', 'Mississippi', 'Mississippi_River', 'Missouri', 'Missouri_River', 'Mobile', 'Mobile_River', 'Mohawk_River', 'Monongahela', 'Monongahela_River', 'Moreau_River', 'Murray', 'Murray_River', 'Murrumbidgee', 'Murrumbidgee_River', 'Namoi', 'Namoi_River', 'Nan', 'Nan_River', 'Neckar', 'Neckar_River', 'Neosho', 'Neosho_River', 'Neva', 'Neva_River', 'New_River', 'Niagara', 'Niagara_River', 'Niger', 'Niger_River', 'Nile', 'Nile_River', 'North_Platte', 'North_Platte_River', 'Ob', 'Ob_River', 'Oder', 'Oder_River', 'Ohio', 'Ohio_River', 'Orange', 'Orange_River', 'Orinoco', 'Orinoco_River', 'Osage', 'Osage_River', 'Outaouais', 'Ottawa', 'Ottawa_river', 'Ouachita', 'Ouachita_River', 'Ouse', 'Ouse_River', 'oxbow', 'oxbow_lake', 'Parana', 'Parana_River', 'Parnaiba', 'Parnahiba', 'Pearl_River', 'Pee_Dee', 'Pee_Dee_River', 'Penobscot', 'Penobscot_River', 'Ping', 'Ping_River', 'Platte', 'Platte_River', 'Po', 'Po_River', 'Potomac', 'Potomac_River', 'Purus', 'Purus_River', 'rapid', 'Rappahannock', 'Rappahannock_River', 'Rhine', 'Rhine_River', 'Rhein', 'Rhone', 'Rhone_River', 'Rio_Grande', 'Rio_Bravo', 'riparian_forest', 'riverbank', 'riverside', 'riverbed', 'river_bottom', 'river_boulder', 'Russian_River', 'Saale', 'Saale_River', 'Sabine', 'Sabine_River', 'Sacramento_River', 'Saint_John', 'Saint_John_River', 'St._John', 'St._John_River', 'Saint_Johns', 'Saint_Johns_River', 'St._Johns', 'St._Johns_River', 'Saint_Lawrence', 'Saint_Lawrence_River', 'St._Lawrence', 'St._Lawrence_River', 'Sambre', 'Sambre_River', 'sandbank', 'San_Joaquin_River', 'Sao_Francisco', 'Saone', 'Saone_River', 'Savannah', 'Savannah_River', 'Scheldt', 'Scheldt_River', 'Seine', 'Seine_River', 'Severn', 'River_Severn', 'Severn_River', 'Severn', 'Severn_River', 'Seyhan', 'Seyhan_River', 'Shari', 'Shari_River', 'Chari', 'Chari_River', 'Shenandoah_River', 'Styx', 'River_Styx', 'Sun_River', 'Suriname_River', 'Surinam_River', 'Susquehanna', 'Susquehanna_River', 'Tagus', 'Tagus_River', 'Tallapoosa', 'Tallapoosa_River', 'Tennessee', 'Tennessee_River', 'Thames', 'River_Thames', 'Thames_River', 'Tiber', 'Tevere', 'Tigris', 'Tigris_River', 'Tocantins', 'Tocantins_River', 'Tombigbee', 'Tombigbee_River', 'Trent', 'River_Trent', 'Trent_River', 'Trinity_River', 'Tunguska', 'Lower_Tunguska', 'Tunguska', 'Stony_Tunguska', 'Tyne', 'River_Tyne', 'Tyne_River', 'Urubupunga', 'Urubupunga_Falls', 'Uruguay_River', 'valley', 'vale', 'Vetluga', 'Vetluga_River', 'Vistula', 'Vistula_River', 'Volga', 'Volga_River', 'Volkhov', 'Volkhov_River', 'Volta', 'waterfall', 'falls', 'water_system', 'Weser', 'Weser_River', 'Willamette', 'Willamette_River', 'Yalu', 'Yalu_River', 'Chang_Jiang', 'Changjiang', 'Chang', 'Yangtze', 'Yangtze_River', 'Yangtze_Kiang', 'Yazoo', 'Yazoo_River', 'Yenisei', 'Yenisei_River', 'Yenisey', 'Yenisey_River', 'Yukon', 'Yukon_River', 'Zambezi', 'Zambezi_River', 'Zhu_Jiang', 'Canton_River', 'Chu_Kiang', 'Pearl_River', 'Charon', 'naiad', 'Achilles', 'finisher', 'Algonkian', 'Algonkin', 'Arikara', 'Aricara', 'Chinook', 'Conoy', 'Halchidhoma', 'Hidatsa', 'Gros_Ventre', 'Kansa', 'Kansas', 'Karok', 'Maidu', 'Maricopa', 'Missouri', 'Mohave', 'Mojave', 'Ofo', 'Omaha', 'Maha', 'Osage', 'Oto', 'Otoe', 'Pamlico', 'Ponca', 'Ponka', 'Quapaw', 'Shahaptian', 'Sahaptin', 'Sahaptino', 'Shawnee', 'Tsimshian', 'Walapai', 'Hualapai', 'Hualpai', 'Yeniseian', 'Yakut', 'charioteer', 'driver', 'honker', 'lasher', 'mahout', 'nondriver', 'road_hog', 'roadhog', 'speeder', 'speed_demon', 'tailgater', 'teamster', 'test_driver', 'wagoner', 'waggoner', 'Cartier', 'Jacques_Cartier', 'Oldfield', 'Barney_Oldfield', 'Berna_Eli_Oldfield', 'debacle', 'bald_cypress', 'swamp_cypress', 'pond_bald_cypress', 'southern_cypress', 'Taxodium_distichum', 'Montezuma_cypress', 'Mexican_swamp_cypress', 'Taxodium_mucronatum', 'pistia', 'water_lettuce', 'water_cabbage', 'Pistia_stratiotes', 'Pistia_stratoites', 'great_yellowcress', 'Rorippa_amphibia', 'Nasturtium_amphibium', 'giant_reed', 'Arundo_donax', 'Phragmites', 'genus_Phragmites', 'black_birch', 'river_birch', 'red_birch', 'Betula_nigra', 'river_red_gum', 'river_gum', 'Eucalyptus_camaldulensis', 'Eucalyptus_rostrata', 'false_indigo', 'bastard_indigo', 'Amorpha_fruticosa', 'thermal_pollution', 'water_pollution', 'alluvial_soil', 'Senegal_gum', 'silt']

But it seems like there are still some noise from the "brute force" method. Let's try to assume that if it is the name of the river it should start with an uppercase, so let's try:

list(chain(*[ [j for j in i.lemma_names if j[0].isupper()] for i in wn.all_synsets() if "river" in i.definition]))

[out]:

['Acheronian', 'Acherontic', 'Stygian', 'Lao', 'Aegospotami', 'Aegospotamos', 'Yalu_River', 'Gasterosteus_aculeatus', 'Gasterosteus_pungitius', 'Cryptobranchus_alleganiensis', 'Scaphiopus_bombifrons', 'Pseudemys_concinna', 'Trionyx_spiniferus', 'Trionyx_muticus', 'Anas_acuta', 'Ancylus', 'Palaemon_australis', 'Platanistidae', 'Hippopotamus_amphibius', 'Australian_lungfish', 'Queensland_lungfish', 'Neoceratodus_forsteri', 'Alosa_pseudoharengus', 'Pomolobus_pseudoharengus', 'Oncorhynchus_nerka', 'Salmo_trutta', 'Australian_arowana', 'Dawson_River_salmon', 'Scleropages_leichardti', 'Australian_bonytongue', 'Scleropages_jardinii', 'Roccus_saxatilis', 'Tilapia_nilotica', 'Chinese_paddlefish', 'Psephurus_gladis', 'Augean_stables', 'Lake_Volta', 'L-plate', 'Phillips_screwdriver', 'Copehan', 'Volgaic', 'Teamsters_Union', 'Mammoth_Cave_National_Park', 'Zion_National_Park', 'Yangon', 'Rangoon', "N'Djamena", 'Ndjamena', 'Fort-Lamy', 'Kinshasa', 'Leopoldville', 'Saxony', 'Sachsen', 'Saxe', 'Cologne', 'Koln', 'Mannheim', 'Rhineland', 'Rheinland', 'Ruhr', 'Ruhr_Valley', 'West_Bank', 'Pennines', 'Pennine_Chain', 'Ottawa', 'Canadian_capital', 'Antwerpen', 'Antwerp', 'Anvers', 'Orleans', 'Rhone-Alpes', 'Friesland', 'Timbuktu', 'Bydgoszcz', 'Bromberg', 'Novosibirsk', 'Tbilisi', 'Tiflis', 'Toledo', 'Selma', 'Denver', 'Mile-High_City', 'Hartford', 'Savannah', 'Topeka', 'Louisville', 'New_Orleans', 'Detroit', 'Motor_City', 'Motown', 'Minneapolis', 'Saint_Paul', 'St._Paul', 'Jefferson_City', 'Saint_Louis', 'St._Louis', 'Gateway_to_the_West', 'Billings', 'Great_Falls', 'Omaha', 'Concord', 'Manchester', 'Trenton', 'Albuquerque', 'New_Netherland', 'Albany', 'Erie_Canal', 'New_York', 'New_York_City', 'Greater_New_York', 'West_Point', 'Niagara_Falls', 'Schenectady', 'Bismarck', 'Fargo', 'Cincinnati', 'Tulsa', 'Chester', 'Philadelphia', 'City_of_Brotherly_Love', 'Pierre', 'Mount_Vernon', 'Charleston', 'Huntington', 'Morgantown', 'Parkersburg', 'Wheeling', 'Casper', 'Ciudad_Bolivar', 'Aare', 'Aar', 'Aare_River', 'Acheron', 'River_Acheron', 'Adige', 'River_Adige', 'Aire', 'River_Aire', 'Aire_River', 'Alabama', 'Alabama_River', 'Allegheny', 'Allegheny_River', 'Amazon', 'Amazon_River', 'Amur', 'Amur_River', 'Heilong_Jiang', 'Heilong', 'Angara', 'Angara_River', 'Tunguska', 'Upper_Tunguska', 'Apalachicola', 'Apalachicola_River', 'Araguaia', 'Araguaia_River', 'Araguaya', 'Araguaya_River', 'Aras', 'Araxes', 'Arauca', 'Argun', 'Argun_River', 'Ergun_He', 'Arkansas', 'Arkansas_River', 'Arno', 'Arno_River', 'River_Arno', 'Avon', 'River_Avon', 'Upper_Avon', 'Upper_Avon_River', 'Avon', 'River_Avon', 'Bighorn', 'Bighorn_River', 'Big_Sioux_River', 'Brahmaputra', 'Brahmaputra_River', 'Brazos', 'Brazos_River', 'Caloosahatchee', 'Caloosahatchee_River', 'Cam', 'River_Cam', 'Cam_River', 'Canadian', 'Canadian_River', 'Cape_Fear_River', 'Chao_Phraya', 'Charles', 'Charles_River', 'Chattahoochee', 'Chattahoochee_River', 'Cimarron', 'Cimarron_River', 'Clinch_River', 'Clyde', 'Cocytus', 'River_Cocytus', 'Colorado', 'Colorado_River', 'Colorado', 'Colorado_River', 'Columbia', 'Columbia_River', 'Congo', 'Congo_River', 'Zaire_River', 'Connecticut', 'Connecticut_River', 'Coosa', 'Coosa_River', 'Cumberland', 'Cumberland_River', 'Danube', 'Danube_River', 'Danau', 'Darling', 'Darling_River', 'Delaware', 'Delaware_River', 'Demerara', 'Detroit_River', 'Dnieper', 'Dnieper_River', 'Don', 'Don_River', 'Ebro', 'Ebro_River', 'Elbe', 'Elbe_River', 'Elizabeth_River', 'Euphrates', 'Euphrates_River', 'Flint', 'Flint_River', 'Forth', 'Forth_River', 'Fox_River', 'Ganges', 'Ganges_River', 'Gan_Jiang', 'Kan_River', 'Garonne', 'Garonne_River', 'Gila', 'Gila_River', 'Grand_River', 'Green', 'Green_River', 'Housatonic', 'Housatonic_River', 'Huang_He', 'Hwang_Ho', 'Yellow_River', 'Hudson', 'Hudson_River', 'IJssel', 'IJssel_river', 'Illinois_River', 'Indigirka', 'Indigirka_River', 'Indus', 'Indus_River', 'Irrawaddy', 'Irrawaddy_River', 'Irtish', 'Irtish_River', 'Irtysh', 'Irtysh_River', 'Isere', 'Isere_River', 'James', 'James_River', 'James', 'James_River', 'Jordan', 'Jordan_River', 'Kansas', 'Kansas_River', 'Kaw_River', 'Kasai', 'Kasai_River', 'River_Kasai', 'Kissimmee', 'Kissimmee_River', 'Klamath', 'Klamath_River', 'Kura', 'Kura_River', 'Lake_Chad', 'Chad', 'Lehigh_River', 'Lena', 'Lena_River', 'Lethe', 'River_Lethe', 'Limpopo', 'Crocodile_River', 'Little_Bighorn', 'Little_Bighorn_River', 'Little_Horn', 'Little_Missouri', 'Little_Missouri_River', 'Little_Sioux_River', 'Little_Wabash', 'Little_Wabash_River', 'Loire', 'Loire_River', 'Mackenzie', 'Mackenzie_River', 'Madeira', 'Madeira_River', 'Magdalena', 'Magdalena_River', 'Mekong', 'Mekong_River', 'Merrimack', 'Merrimack_River', 'Meuse', 'Meuse_River', 'Milk', 'Milk_River', 'Mississippi', 'Mississippi_River', 'Missouri', 'Missouri_River', 'Mobile', 'Mobile_River', 'Mohawk_River', 'Monongahela', 'Monongahela_River', 'Moreau_River', 'Murray', 'Murray_River', 'Murrumbidgee', 'Murrumbidgee_River', 'Namoi', 'Namoi_River', 'Nan', 'Nan_River', 'Neckar', 'Neckar_River', 'Neosho', 'Neosho_River', 'Neva', 'Neva_River', 'New_River', 'Niagara', 'Niagara_River', 'Niger', 'Niger_River', 'Nile', 'Nile_River', 'North_Platte', 'North_Platte_River', 'Ob', 'Ob_River', 'Oder', 'Oder_River', 'Ohio', 'Ohio_River', 'Orange', 'Orange_River', 'Orinoco', 'Orinoco_River', 'Osage', 'Osage_River', 'Outaouais', 'Ottawa', 'Ottawa_river', 'Ouachita', 'Ouachita_River', 'Ouse', 'Ouse_River', 'Parana', 'Parana_River', 'Parnaiba', 'Parnahiba', 'Pearl_River', 'Pee_Dee', 'Pee_Dee_River', 'Penobscot', 'Penobscot_River', 'Ping', 'Ping_River', 'Platte', 'Platte_River', 'Po', 'Po_River', 'Potomac', 'Potomac_River', 'Purus', 'Purus_River', 'Rappahannock', 'Rappahannock_River', 'Rhine', 'Rhine_River', 'Rhein', 'Rhone', 'Rhone_River', 'Rio_Grande', 'Rio_Bravo', 'Russian_River', 'Saale', 'Saale_River', 'Sabine', 'Sabine_River', 'Sacramento_River', 'Saint_John', 'Saint_John_River', 'St._John', 'St._John_River', 'Saint_Johns', 'Saint_Johns_River', 'St._Johns', 'St._Johns_River', 'Saint_Lawrence', 'Saint_Lawrence_River', 'St._Lawrence', 'St._Lawrence_River', 'Sambre', 'Sambre_River', 'San_Joaquin_River', 'Sao_Francisco', 'Saone', 'Saone_River', 'Savannah', 'Savannah_River', 'Scheldt', 'Scheldt_River', 'Seine', 'Seine_River', 'Severn', 'River_Severn', 'Severn_River', 'Severn', 'Severn_River', 'Seyhan', 'Seyhan_River', 'Shari', 'Shari_River', 'Chari', 'Chari_River', 'Shenandoah_River', 'Styx', 'River_Styx', 'Sun_River', 'Suriname_River', 'Surinam_River', 'Susquehanna', 'Susquehanna_River', 'Tagus', 'Tagus_River', 'Tallapoosa', 'Tallapoosa_River', 'Tennessee', 'Tennessee_River', 'Thames', 'River_Thames', 'Thames_River', 'Tiber', 'Tevere', 'Tigris', 'Tigris_River', 'Tocantins', 'Tocantins_River', 'Tombigbee', 'Tombigbee_River', 'Trent', 'River_Trent', 'Trent_River', 'Trinity_River', 'Tunguska', 'Lower_Tunguska', 'Tunguska', 'Stony_Tunguska', 'Tyne', 'River_Tyne', 'Tyne_River', 'Urubupunga', 'Urubupunga_Falls', 'Uruguay_River', 'Vetluga', 'Vetluga_River', 'Vistula', 'Vistula_River', 'Volga', 'Volga_River', 'Volkhov', 'Volkhov_River', 'Volta', 'Weser', 'Weser_River', 'Willamette', 'Willamette_River', 'Yalu', 'Yalu_River', 'Chang_Jiang', 'Changjiang', 'Chang', 'Yangtze', 'Yangtze_River', 'Yangtze_Kiang', 'Yazoo', 'Yazoo_River', 'Yenisei', 'Yenisei_River', 'Yenisey', 'Yenisey_River', 'Yukon', 'Yukon_River', 'Zambezi', 'Zambezi_River', 'Zhu_Jiang', 'Canton_River', 'Chu_Kiang', 'Pearl_River', 'Charon', 'Achilles', 'Algonkian', 'Algonkin', 'Arikara', 'Aricara', 'Chinook', 'Conoy', 'Halchidhoma', 'Hidatsa', 'Gros_Ventre', 'Kansa', 'Kansas', 'Karok', 'Maidu', 'Maricopa', 'Missouri', 'Mohave', 'Mojave', 'Ofo', 'Omaha', 'Maha', 'Osage', 'Oto', 'Otoe', 'Pamlico', 'Ponca', 'Ponka', 'Quapaw', 'Shahaptian', 'Sahaptin', 'Sahaptino', 'Shawnee', 'Tsimshian', 'Walapai', 'Hualapai', 'Hualpai', 'Yeniseian', 'Yakut', 'Cartier', 'Jacques_Cartier', 'Oldfield', 'Barney_Oldfield', 'Berna_Eli_Oldfield', 'Taxodium_distichum', 'Montezuma_cypress', 'Mexican_swamp_cypress', 'Taxodium_mucronatum', 'Pistia_stratiotes', 'Pistia_stratoites', 'Rorippa_amphibia', 'Nasturtium_amphibium', 'Arundo_donax', 'Phragmites', 'Betula_nigra', 'Eucalyptus_camaldulensis', 'Eucalyptus_rostrata', 'Amorpha_fruticosa', 'Senegal_gum']

Let's go crazy and say that only if the word "River" appears in the lemma, it is a river:

>>> list(chain(*[ [j for j in i.lemma_names if j[0].isupper() and "River" in j] for i in wn.all_synsets() if "river" in i.definition]))

[out]:

['Yalu_River', 'Dawson_River_salmon', 'Aare_River', 'River_Acheron', 'River_Adige', 'River_Aire', 'Aire_River', 'Alabama_River', 'Allegheny_River', 'Amazon_River', 'Amur_River', 'Angara_River', 'Apalachicola_River', 'Araguaia_River', 'Araguaya_River', 'Argun_River', 'Arkansas_River', 'Arno_River', 'River_Arno', 'River_Avon', 'Upper_Avon_River', 'River_Avon', 'Bighorn_River', 'Big_Sioux_River', 'Brahmaputra_River', 'Brazos_River', 'Caloosahatchee_River', 'River_Cam', 'Cam_River', 'Canadian_River', 'Cape_Fear_River', 'Charles_River', 'Chattahoochee_River', 'Cimarron_River', 'Clinch_River', 'River_Cocytus', 'Colorado_River', 'Colorado_River', 'Columbia_River', 'Congo_River', 'Zaire_River', 'Connecticut_River', 'Coosa_River', 'Cumberland_River', 'Danube_River', 'Darling_River', 'Delaware_River', 'Detroit_River', 'Dnieper_River', 'Don_River', 'Ebro_River', 'Elbe_River', 'Elizabeth_River', 'Euphrates_River', 'Flint_River', 'Forth_River', 'Fox_River', 'Ganges_River', 'Kan_River', 'Garonne_River', 'Gila_River', 'Grand_River', 'Green_River', 'Housatonic_River', 'Yellow_River', 'Hudson_River', 'Illinois_River', 'Indigirka_River', 'Indus_River', 'Irrawaddy_River', 'Irtish_River', 'Irtysh_River', 'Isere_River', 'James_River', 'James_River', 'Jordan_River', 'Kansas_River', 'Kaw_River', 'Kasai_River', 'River_Kasai', 'Kissimmee_River', 'Klamath_River', 'Kura_River', 'Lehigh_River', 'Lena_River', 'River_Lethe', 'Crocodile_River', 'Little_Bighorn_River', 'Little_Missouri_River', 'Little_Sioux_River', 'Little_Wabash_River', 'Loire_River', 'Mackenzie_River', 'Madeira_River', 'Magdalena_River', 'Mekong_River', 'Merrimack_River', 'Meuse_River', 'Milk_River', 'Mississippi_River', 'Missouri_River', 'Mobile_River', 'Mohawk_River', 'Monongahela_River', 'Moreau_River', 'Murray_River', 'Murrumbidgee_River', 'Namoi_River', 'Nan_River', 'Neckar_River', 'Neosho_River', 'Neva_River', 'New_River', 'Niagara_River', 'Niger_River', 'Nile_River', 'North_Platte_River', 'Ob_River', 'Oder_River', 'Ohio_River', 'Orange_River', 'Orinoco_River', 'Osage_River', 'Ouachita_River', 'Ouse_River', 'Parana_River', 'Pearl_River', 'Pee_Dee_River', 'Penobscot_River', 'Ping_River', 'Platte_River', 'Po_River', 'Potomac_River', 'Purus_River', 'Rappahannock_River', 'Rhine_River', 'Rhone_River', 'Russian_River', 'Saale_River', 'Sabine_River', 'Sacramento_River', 'Saint_John_River', 'St._John_River', 'Saint_Johns_River', 'St._Johns_River', 'Saint_Lawrence_River', 'St._Lawrence_River', 'Sambre_River', 'San_Joaquin_River', 'Saone_River', 'Savannah_River', 'Scheldt_River', 'Seine_River', 'River_Severn', 'Severn_River', 'Severn_River', 'Seyhan_River', 'Shari_River', 'Chari_River', 'Shenandoah_River', 'River_Styx', 'Sun_River', 'Suriname_River', 'Surinam_River', 'Susquehanna_River', 'Tagus_River', 'Tallapoosa_River', 'Tennessee_River', 'River_Thames', 'Thames_River', 'Tigris_River', 'Tocantins_River', 'Tombigbee_River', 'River_Trent', 'Trent_River', 'Trinity_River', 'River_Tyne', 'Tyne_River', 'Uruguay_River', 'Vetluga_River', 'Vistula_River', 'Volga_River', 'Volkhov_River', 'Weser_River', 'Willamette_River', 'Yalu_River', 'Yangtze_River', 'Yazoo_River', 'Yenisei_River', 'Yenisey_River', 'Yukon_River', 'Zambezi_River', 'Canton_River', 'Pearl_River']

Much better but i think you're better off just crawling the names from http://en.wikipedia.org/wiki/Lists_of_rivers . Have fun!

Answer 2

To show that the solution for "river" using NLTK wordnet won't scale other entities, and also answer @tripleee's question.

If you're looking for animals , you can simply recursively get all hyponyms of animals, as such:

list(set([w for s in vehicle.closure(lambda s:s.hyponyms()) for w in s.lemma_names]))

Answer 3

We can use sentence tagging to get proper nouns. Filter them for required output.

Perhaps:

  from nltk.tag import pos_tag
  sentence = "Amazon is great river. Mississippi is awesome too."
  tagged_sent = pos_tag(sentence.split())

  tagged_sent will yield similar tagged out where NNP is the proper noun.

[('Amazon', 'NNP'), ('is', 'VBZ'), ('great', 'JJ'), ('river.', 'NNP'), ('Mississippi', 'NNP'), ('is', 'VBZ'), ('awesome', 'VBN'), ('too.', '-NONE-')]

   propernouns = [word for word,pos in tagged_sent if pos == 'NNP']
   propernouns would return
   ['Amazon', 'river.', 'Mississippi']

You can set categories for each and use a function to return them.

Answer 4

If you want to get lists of things of a specific type eg rivers http://dbPedia.org , http://freebase.com or http://wikidata.org are the better choice.

This dbPedia SPARQL query returns all rivers known to Wikipedia:

SELECT ?name ?description WHERE {
   {?river rdf:type dbpedia-owl:River} .
    ?river foaf:name ?name .
    ?river rdfs:comment ?description .
}
ORDER BY ?name

http://bit.ly/1jc8Ip6