Python collection type built-in method summary

 

Collection (s). Method name	Equivalent symbol	Method description
S.issubset (t)	S <= t	Subset testing (allows for a subset of non-strict meanings): All elements in S are members of T
	S < T	Subset testing (STRICTLY): s! = T and all elements in s are members of T
S.issuperset (t)	S >= t	Hyper-set test (allows for non-strict superset): All elements in T are members of S
	s > t	Hyper-Set testing (STRICTLY): s! = T and all elements in T are members of S
S.union (t)	s | T	Merge operation: Elements in S "or" t
S.intersection (t)	S & T	Intersection operations: Elements in S "and" t
S.difference	S-t	Differential operation: An element that exists in s that does not exist in T
S.symmetric_difference (t)	s ^ t	Symmetric differential operation: elements in S "or" T, but not elements common to s and T
S.copy ()		Returns a copy of S (Shallow copy)
The following methods apply only to mutable collections
S.update	S |= t	Add an element from T to S
S.intersection_update (t)	S &= t	Intersection modification operation: s includes only members of S and T
S.difference_update (t)	S-= t	Difference modification operation: s includes members that belong only to s but are not part of T
S.symmetric_difference_update (t)	S ^= t	Symmetric differential modification operation: s includes only members belonging to s or only t
S.add (obj)		Add an action: adding obj to S
S.remove (obj)		Delete operation: Removes obj from S and throws an exception if obj does not exist in S
S.discard (obj)		Discard operation: Remove obj from S, and if obj is not present in S, it's okay ^_^
S.pop ()		Eject action: Remove and return any element in S
S.clear ()		Clear action: Clears all elements in s

Python collection type built-in method summary