List

Creation

	command	Q	Python	Q example	Python example	comment
	creating general list	( ) with separator ;	[ ] with separator ,	l: (3; 1.0; "hello")	l = [3, 1.0, "hello"]
💙	creating homogenious list	whitespace is the separator		li: 3 1 2	li = [3, 1, 2]	Q saves you some typing
💛	list of a single item	keyword enlist	no special treatment	enlist 3	[3]	Need of using enlist is confusing
	list of pairs from two lists	, '	zip	l1 ,' l2	zip(l1, l2)
💙	list of generated ints	til	range and list	til 3	list(range(3))
💛	list of generated ints between	not supported, workaround exists		3 + til 7-3	list(range(3,7))
💛	list of generated ints with steps	workaround exists		4 + 2 * til (10 - 4) div 2	list(range(4,10, 2))

Modification

	command	Q	Python	Q example	Python example	comment
	append	,:	append	l,: 3	l.append(3)
💙	extend	,:	extend	l1,: l2	l1.extend(l2)	Q implements polymorphism better
💛	insert into middle	not supported, workaround exists	insert	(i#l), x, i_l	l.insert(i, x)
	delete by index	#	del	l: (3#l), 4_l	del l[3]
	delete all	#	clear	l: 0#l	l.clear()
💛	pop last element	not supported, workaround exists	pop		l.pop()
💛	remove value	: and except	remove	l: l except 3	l.remove(3)
💙	remove multiple values			l1 except l2	[e for e in l1 if e not in l2]

Lookup

	command	Q	Python	Q example	Python example	comment
	find first	?	index	l ? 3	l.index(3)
💙	find multiple	?	not supported	l ? 3 7
💙	find all occurrences	= where		where 3 = l	[i for i, x in enumerate(l) if x == "3]
💙	position of all occurrences of elements	group	not supported	group 1 2 1 3 3
💙	unique values	distinct	manually convert to set	distinct l	list(set(l))
💙	intersection	inter		l1 inter l2	list(set(l1) & set(l2)) or set(l1).intersection(l2)
💙	union	union		l1 union l2	list(set(l1) | set(l2)) or set(l1).union(l2)
💙	first/last element as monadic function	first/last	not supported	first l
	first/last n rows	#	[:]	15#l -3#l	l[:15] l[-3:]
💙💙	indexing by list	same as index by number	workaround with for loop	l[0 3 9]	[l[i] for i in [0, 3, 9]]]	Q is more elegant and requires less typing. Class array in Numpy also supports indexing by list

Operators

	command	Q	Python	Q example	Python example	comment
	concatenation	,	+	l1, l2	l1 + l2
	equivalence	~	==	l1 ~ l2	l1 == l2
	empty list check	count	not	0 = count l	not l
	lexicographical comparison	not first iasc	<=	not first iasc (l1; l2)	l1 < l2	In Q operators < and * is reserved for elementwise comparison
	list repetition	raze enlist	*	raze 3#enlist l	3*l
💙💙	elementwise operators	by design	not suported
	sorting	asc	sorted	asc l	sorted(l)	inplace sorting in only supported in Python by function sort
💙		desc		desc l	sorted(l, reverse=True)
💙	overwrite null only	^	not supported	(1 2) ^ 0N 4