Set Methods

Python · Methods reference

Python · Methods reference

📋 Overview

All set and frozenset methods (frozenset lacks mutating methods).

🔧 Methods

Mutating (set only)

Method	Description
`add(elem)`	Add element
`remove(elem)`	Remove; KeyError if missing
`discard(elem)`	Remove if present
`pop()`	Remove and return arbitrary element
`clear()`	Remove all
`update(*others)`	Union in place
`intersection_update(*others)`	&= in place
`difference_update(*others)`	-= in place
`symmetric_difference_update(other)`	^= in place

Non-mutating / both types

Method	Description
`union(*others)`	New set with all elements
`intersection(*others)`	Elements in all sets
`difference(*others)`	In self but not others
`symmetric_difference(other)`	In exactly one set
`isdisjoint(other)`	No shared elements
`issubset(other)` / `issuperset(other)`	Subset / superset test
`copy()`	Shallow copy (set only)

💡 Examples

See parent topic notes for runnable snippets; this page is the complete method index.

⚠️ Pitfalls

Mutating methods return None in Python — do not chain sort() / reverse() expecting a new list.
Default JS sort() compares strings — pass (a,b) => a-b for numbers.
SQL function names differ by dialect — verify Postgres vs MySQL docs.
Django QuerySet.update() skips save() signals and auto auto_now fields on models.

Sets

List Methods

Python · Methods reference

String Methods

Python · Methods reference

On this page

📋 Overview 🔧 Methods Mutating (set only)Non-mutating / both types 💡 Examples ⚠️ Pitfalls 🔗 Related