Python Sets Cheat Sheet by Nouha_Thabet

Set

 A set is a collection which is unordred and unindexed in a way that we cannot be sure in which order the items will appear.

Set Example

 `RYB_color = {"Re­d","Y­ell­ow",­"­Blu­e"} print(­RYB­_color) >>> {'Red'­,'Y­ell­ow'­,'B­lue'}`

The set() Constr­uctor

 `RYB_color = set(("R­ed",­"­Yel­low­"­,"Bl­ue"))`

Access Items

 Example 1 `for x in RYB_color:  ­ ­ ­  print(x) >>> Red >>> Yellow >>> Blue ` Example 2 `print­("Ye­llo­w" in RYB_color) >>> True`

Change Items

 Since a set is not orderer neither indexed, then we cannot acces to any item to change its value.

 `RYB_c­olo­r.a­dd(­"­Whi­te") print(­RYB­_color) >>> "­Red­"­,"Wh­ite­"­,"Ye­llo­w","B­lue­"`

Get the Length of a Set

 `print­(le­n(R­YB_­color)) >>> 3`

Delete a set

 `del RYB_color`

Remove Item

 `RYB_c­olo­r.r­emo­ve(­"­Yel­low­") print(­RYB­_color) >>> {'Red'­,'B­lue'}` If the item doesn't exist then `remove()` will raise an error. `RYB_c­olo­r.d­isc­ard­("Ye­llo­w") print(­RYB­_color) >>> {'Red'­,'B­lue'}` If the item doesn't exist then `disca­rd()` will raise an error. `c = thisse­t.pop() print(c) print(­thi­sset) >>> Yellow {{nl}] >>> {'Red'­,'B­lue'}` Since a set is not orderer neither indexed, then we cannot change acces to any item to change its value. `RYB_c­olo­r.c­lear()` `clear()` returns an empty set.

Join Two Sets

 `Secon­d_color = {"Gr­een­"­,"Or­ang­e","P­urp­le"} Color = RYB_co­lor.un­ion­(Se­con­d_c­olor) print(­Color) >>> {'Yell­ow'­,'O­ran­ge'­,'R­ed'­,'G­ree­n',­'Bl­ue'­,'P­urp­le'}` `union()` joins two sets into a new one and excludes any duplicate items. `RYB_c­olo­r.u­pda­te(­Sec­ond­_color) print(­RYB­_color) >>> {'Yell­ow'­,'O­ran­ge'­,'R­ed'­,'G­ree­n',­'Bl­ue'­,'P­urp­le'}` `update()` inserts the items in `Secon­d_c­olor` into `RYB_c­olor` and excludes any duplicate items.

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