Module:NUMBEROFSECTIONS

local p = {}

local function trimArg(arg, i)
	arg = mw.text.trim(arg or '')
	if arg == '' then
		if i then
			error('Parameter ' .. i .. ' is missing. See [[Template:NUMBEROF]] documentation')
		end
		return nil
	end
	return mw.ustring.lower(arg)
end

local function getIfLocal(site, action)
	-- If wanted site is the local site where module is running,
	-- return numberof result for given action, or nil.
	-- This is faster than reading the cached table, and gives the current value.
	local localSite = string.match(mw.site.server, '.*//(.*)%.org$')  -- examples: 'en.wikipedia', 'commons.wikimedia'
	if site == localSite then
		if action == 'activeusers' then
			action = 'activeUsers'
		end
		return mw.site.stats[action]
	end
end

function p.numberof(frame)
	local args = frame:getParent().args
	local action = trimArg(args[1], 1)  -- activeusers, admins, articles, edits, files, pages, users
	local site = trimArg(args[2], 2)  -- "en" or "en.wikipedia" or "en.wikiquote" etc.
	if not site:find('.', 1, true) then
		site = site .. '.wikipedia'
	end
	local wantComma = trimArg(args[3])  -- nil for no commas in output; "N" or anything nonblank inserts commas
	local result = getIfLocal(site, action)
	if not result then
		local data = mw.loadData('Module:NUMBEROF/data')
		local map = data.map
		data = data.data
		result = data[site]
		if result then
			result = result[map[action]]
		end
	end
	if result then
		if wantComma then
			result = mw.getContentLanguage():formatNum(result)
		end
		return result  -- number or formatted string
	end
	return '-1'
end

-- Unescape functionality grabbed from https://stackoverflow.com/a/14899740/1832568
local function unescape(str)
	str = string.gsub(str, '&#(%d+);', string.char)
	str = string.gsub(str, '&#x(%d+);', function(n) return string.char(tonumber(n, 16)) end)
	return str
end

-- Counting function accepting a string haystack and table of needles
local function count(haystack, needles)
	local number = 0
	-- While we have needles to look for
	for index, needle in ipairs(needles) do
		-- find them all in our haystack
		for m in string.gmatch(haystack, needle) do
			number = number + 1
		end
	end
	return number
end

-- Function takes any number of # delimited page names and section level numbers
function p.sections(frame)
	local total = 0
	local needles = {}
	local haystack = ''
	-- Separate page names from # delimited string into table
	local pages = mw.text.split(unescape(frame.args[1]), '%s?#%s?')
	-- Separate whitespace delimited section level numbers into table
	local levels = mw.text.split(frame.args['level'], '%s*')
	-- Iterate through levels
	for level in mw.text.gsplit(table.concat(levels), '') do
		-- and add the level needle to needles
		needles[#needles + 1] = '\n'..string.rep('=', tonumber(level))..'[^=]'
	end
	-- For each page name in pages
	for index, page in ipairs(pages) do
		-- create a haystack to search from the page content
		haystack = mw.title.new(page):getContent()
		-- If we've requested the content of a legitimate page
		if haystack then
			--[[ pass the raw markup and needles to count
				 and add the return to total ]]
			total = total + count('\n' .. haystack, needles)
		end
	end
	--[[ then return how many sections of the required level
		 are in all the pages passed ]]
	return total
end

return p
Usage
