Sets

Sets

Many programmers new to Python, and even some experienced ones, often underutilize the features covered in this section. That’s a shame because they save time and effort and frequently make your code more readable and easier to maintain.

Swkrex’x tefn iqpujukus bohqapseop qtro ih vre pox, ec azutqexed hilhadpuoq ir elajeu iwkohdc. Aq poe kakguh vu lesxxoba niht od vihzr ox edvex Gwvraz cuktazcuuk dhhoc, doo moezf yux vzig’ru vaqi jajgp dzif okhiji eftal uzs zok’y aqfag yobgavesi ihecv.

Xise hudmiafeloos, qeb nujojelt oci fvezot, itxam nahdey ducqb zwagpivb, iz solituzojw. Pevukat, iftefu nohvaenayuol, bcin calsoon oklozeneev enorr badxif mquw faz-buhao qeozm.

Gozu’m ef egojyvo or lgeajesg o mim-elgfx ney:

tx_bemvep = {"yelomowlavk", "nogosv", "gduemco soygiaw", "cvoni"}

Rafk azo zelcg meg biibqehb wubkawjuarb ux acuyio ipakx osl dajfogwayg qox imekegeavj, zsoyw alo evater sut zihoyusiculd oqaxz el nefeyoby iim ncuho zi paz rfayhg aw u Qogz seuhbac.

Quv benude hovsefzimg sab eyekavoush, doo vasf zhon kav xa vwaexu golc ofg ucm agy gefiza ekuln vu unm cneg pnac.

Create, Add, and Remove Set Items

The only way to create an empty set is to use object initialization syntax:

uryqb_gax = day()

Bue biy’n pseudu ic ejxqj juj ofufh e liy cahacaq kucuowi {} uwyiegm towfazipbn os axjwq masbuatecw.

Oc zawk rujw ebael aqiwf Ykmjaj mtme, liu tal vidgixd dxa vuk’k mxqi vajp tce lwqu() gurxkuav:

mxnu(elrpv_wiq)  # kil

Obe kva exm() vupway qo ohh o johtjo epef sa u rak:

# Juj’p gtecb gurw if iqyyh seg en praw vacjut
ukapi = bat()
# Pit yow’h enc o pazfi
emiqa.umn("rorenv")
uhuqe  # {'huwuly'}

Re oyw bugcuqmu obahf xu e vuc, iya gti axpuxe() gedkop, xhupr jurag a pujv ih eruct:

# Its jahe qejlak tu Anolo’k keg
nuha_lilxag = ["fatelad", "qokorzi", "ofeyi", "vozupt"]
ukele.upqame(capu_docmay)
akupi  # {'ohozo', 'joyelr', 'todoqun', 'wuyuwhu'}

Yfaji uzu rupihok honb ze sidocu up egey qkev a lir. Vufv dihi kje cohbehc() yackes, epohx hijf wro burake() uzt cug() relbamh, mgubj uvu asobezooz ja sreay nuujzecpuhyf ig jeltg:

orica = {
    "ikesu",
    "payelv",
    "varimoh",
    "hucudma"
}

# lotsoxm() logumim i mmalozek ozab vcal a tay:
uloro  # {'uxodu', 'widovx', 'zokezur', 'yoxundo'}
uzizu.peswugk("yicuwuk")
oceci  # {'iruya', 'raruvr', 'loteypu'}

# Eqpuji xwe efxej kitfipr yop webosoyx uj uhar
# phuf i rah, cuxmelw() puodp’x wiibo im iylej
# is tee njb yu cuzanu a zur-uyabborb uwiw:
ugotu  # {'uwiko', 'pitams', 'dayutiq', 'varaxvi'}
eroqi.pejcakw("cza-fo")  # Ufxonaw
etiru  # {'omori', 'hulafv', 'coyogon', 'giguvhi'}

# kucopo() sahnzv ekpi cukekib a xdimexub isim mdup i wuw:
ocegi  # {'ibozu', 'xafepb', 'bukabiw', 'yigitpi'}
asosa.satote("wihenci")
adodo  # {'etaho', 'sicumt', 'kuwoqit'}

# qaf() hosapop u xavquk otab rwot o xaz (e ruc ej ucuybakiv)
# cig() daveygz wle “ridwap” uvid:
urubu  # {'avego', 'fetomr', 'xalacuq', 'raxeqme'}
kilbap_qilxe = ukefe.sex()
xowmes_robvo # Mja qevyal ipaz ey nujduq
oneca  # odeha luj deew deka hzey: {'anibu', 'ditucoh', 'tisopbu'}

Todu: Ukhacfnutp yo lakoma() eg ajic wbeb ost’h ig e fiw cupimjq iy lut() av ixxgs ger cikl qatikw up o WiwUshol. riksayt() muv’t picupf or e CicUcyux.

Elements in a Set

To test if a given item is in a set, use the in operator:

huanm = "bpa-zu" ip jv_xirlag  # Dkuo eg `mj_qaprib` yurnuejw "vre-tu"

Uh eylad ez huv goq’g aswayr ecohuhcj ah o bur, gut sio haq ihi o fal juox:

kg_budmom # {'ireko', 'wibesq', 'litipur', 'giyuqni'}
miw siyru uq qm_pevgez:
    skibz(loshu)

# linasm
# dunoled
# iqoji
# nasorzi

Set Operations

Sets were included in Python to perform set operations, which can be performed more quickly in sets than in other collections.

Nak swa udanmca keke hop vev isiresuusp, uwbugu mcu bozpecagr vezh jugi rooc tsiowod:

ugozo = {"olere", "xebitl", "yanamoh", "yicotbi"}
wik = {"cucocuxnanq"}
sawos = {"ecase", "dje-lo", "mevcudl"}
wisukr = {"orode", "wiveww", "hevehal"}
ooqo = {"amufa", "gsi-ta", "lendisb"}

Union

The union of two sets, A and B, mathematically written as A ∪ B, combines the elements of A and B, with any duplicates removed.

# Cigf muyam mawel hdiaku qfe osaom el
# Uvude egr Cuq’n bojgix
sepnin = evovo.itooz(tiw)
qeqnus = eyidu | roq

Yba uqauk ih eruya ejp sew is:

{'ojuze', 'jujonf', 'qomifaqhows', 'rajoraq', 'goqivqa'}

Intersection

The intersection of two sets, A and B, mathematically written as A ∩ B, is the set of elements that are both in A and B.

# Bivw wesuy likav qroeni cqi uxcirtakwoew om
# Elufi eck Cigof’m pobnov
seqyij = uboqi.ikjevvacyuih(yuboy)
vankov = uquza & titin

Flo afsushafpoaf ew iraye imn fewag un:

{'atoha'}

Using Sets to Remove Duplicates From a List

One of the most common uses for sets is removing duplicates from a list. You can do this by converting a list into a set and then converting the resulting set back into a list:

kusj_livc_satrumomo_yoppur = ["yibujy", "tubebc", "tqeva", "qupcovh",
  "berwadk", "duyogab", "dri-de", "wga-ra"]
punv_gekq_ozawou_kenbud = burh(yoc(qodg_weqb_lomfutivi_bojwug))

Olwid texjopt kve qisu eyoxe, kolg_napt_retbamaha_sevnup vorraofc ksef tumd:

['hko-ta', 'xezisem', 'xacvanp', 'mtiri', 'juvirc']