Rearranging & Restructuring Lists
The Wolfram Language encapsulates in a small number of functions vast flexibility in rearranging lists with any structure and any number of elements.
Flatten — flatten out any sequence of levels in a nested list
Partition — partition lists or nested lists into sublists
Join — join lists together at any level
Catenate — catenate elements from a list of lists
ArrayFlatten ▪ ArrayReshape ▪ FlattenAt ▪ Splice ▪ Nothing
TakeList — take a succession of sublists from a list
Sort — sort lexicographically or with any comparison function
ReverseSort — sort reverse lexicographically
SortBy — sort by the values of a function applied to elements
AlphabeticSort ▪ NumericalSort ▪ LexicographicSort ▪ ReverseSortBy
Reverse — reverse a list at any level
RotateLeft , RotateRight — cyclically rotate lists at any depth
Transpose — transpose any collection of levels
ArrayReduce — reduce dimensions of an array by applying a function
ArrayResample — resample an array to higher or lower resolution
ArrayPad — add padding on each side
ArrayFilter — filter an array using local neighborhoods
Riffle — intersperse additional elements
PadLeft , PadRight — pad lists to be a particular length at any depth
Split — split into runs of identical elements
Gather — gather sublists of identical elements
Union , Tally — enumerate, tally all distinct elements in a list
DeleteDuplicates — delete duplicate elements in a list
DeleteDuplicatesBy — delete elements for which values of a function are duplicated
DeleteAdjacentDuplicates — delete duplicates adjacent to one another
SplitBy , GatherBy — split, gather based on values of a function applied to elements
Tuples ▪ Subsets ▪ Subsequences ▪ Permutations ▪ RandomSample
Groupings — generate all possible groupings of a list into sublists
Union ▪ Intersection ▪ Complement
Sequence-Oriented Operations
SequenceSplit — split a list at sequences matching a pattern
SequenceReplace — replace sequences in a list
Element-Oriented Operations »
ReplacePart ▪ Take ▪ Drop ▪ Append ▪ AppendTo