Products quantities

How to handle it

Existing libraries to parse weights and quantities

• https://github.com/iancanderson/ingreedy

Using Wikidata

• Translations and aliases of units
  • List of Units in multiple languages on Wikidata

• weight unit list
  • Units of weight list on Wikidata
• units of volume
  • Units of volume list on Wikidata

Possible calculations

• Weight per item
  • Is the same item always the same weight (ham slices)
  • Useful if you eat one of the cakes in the packaging, and want to know how many calories you ate without having to weight the cake
• Percentage of water
  • Useful to calculate actual cost if we know the price
  • Useful to fix calorie calculation for some products
• Calculate packaging weight by making the difference between actual weight and advertised weight
• Calculate weight per volume for products (1dL of water is 1kg, but this changes for various products that also have a mention of their volume)
• Some products will have multilingual weights
  • we can check that the conversion is well done if we have both values
  • we can display the value in several metrics if we have a sanitized value in one metric

Generic approach

The real-world quantities for products as used by the users us a far from ideal. However it is possible to find some common approach. (At least we try here)

• to indicate times, either a "*" or a "x" can be used;
• the generic formula is: multiplier * quantity size_unit for units
• multiple formulas are distinguished by a ";"
  • multiplier indicates how often a quantity unit is used, i.e. 6 (25 cl bottles). This is a number.
  • quantity the size of the units in size_units, i.e. 25 (size) cl (size_unit) bottles (units). This is a number.
  • size_units is the unit for the size parameter, i.e. kg, ml or cl. This is an enumerated?
  • unit is the element the numbers and sizes refer to, i.e. pot, bottle, sack, etc.

Some remarks:

• not all 4 elements are always specified, eg 250 g means 1*250 g for the entire product
• sometimes more than one quantity is specified, e.g. 250 g (5x50 g) might mean 1x250g for the entire product OR 5 50g pots
• there are exceptions, such as multiple multipliers.
• naturally users do not use this formal approach, but most quantities can be translated to this approach.

Test: To test this approach the examples found in France have translated to this formal approach:

Quantity as stated by user	Multiplier	Quantity	Size_unit	Units
1 kg (8 pots) - [2 x (4 x 125 g)]	-	1	kg	-
or	8	-	-	pots
or	2x4	125	g	-
275 g [250 g + 25 g (10 %) gratuit]
2 * 400 g (800 g)
4X100g	4	100	g	-
2*25g	2	25	g	-
200 g [160 g (2 x 8 pièces) mini-nems + 40 g sauce nuoc mâm]
211,5 g (9x23,5g)	-	211,5	g	-
or	9	23,5	g	-
220g (2 unités, 2 x (60 g + 50 g))
2 x 21.5 g = 43 g
300 g (15 biscuits de 20 g)
1 Litre	-	1	litre	-
18tranche	18	-	-	tranches
375 g, 30 pièces	-	375	g	-
or	30	-	-	pièces
240 g (12 Portions)	-	240	g	-
or	12	-	-	portions
400 g (12 à 18 bouchées)
Poids net 190 g, poids net égoutté 140 g
contenance : 4250ml, poids net total : 4000g, poids net égoutté : 2210g
3 x [200 g (130 g net égoutté), 212 ml]
330 g (dont 180 g net), 370 mL
28 g - 20 dragées	-	28	g	-
or	20	-	-	dragées
260 g (26 portions de 10 g)
130 g pour 20 galettes	-	130	g	-
or	20	-	-	galettes
280 ml - 310 g
25 sachets	25	-	-	sachets
220 g (1 personne)
128 g (16 bâtonnets de 2 cubes)	-	128	g	-
or	16	-	-	bâtonnets
or	16x4	-	-	cubes	12 (calibre Moyen => 53 à 63 g)	12	-	-	calibre moyen
8 sachets de 4	8	-	-	sachets
or	8x4	-	-	-
400 g, 425 ml (3 douzaines)
228g (4x57g) / 48 cl (4x12cl)

Countries

France

Product name	Quantity as stated by user	Product page URL
Brassé nature	1 kg (8 pots) - [2 x (4 x 125 g)]	(link)
Emmental Coeur de Meule (28 % MG)	275 g [250 g + 25 g (10 %) gratuit]	(link)
Basilico	2 * 400 g (800 g)	(link)
Frais Malo Sucré	4X100g	(link)
Twix	2*25g	(link)
16 mini-nems Poulet, menthe, Légumes, coriandre - Précuits - Surgelés	200 g [160 g (2 x 8 pièces) mini-nems + 40 g sauce nuoc mâm]	(link)
9 barres au chocolat au lait et aux céréales	211,5 g (9x23,5g)	(link)
Fondant au chocolat	220g (2 unités, 2 x (60 g + 50 g))	(link)
Kinder Bueno	2 x 21.5 g = 43 g	(link)
Prince Goût Chocolat	300 g (15 biscuits de 20 g)	(link)
Eau minérale Contrex	1 Litre	(link)
Brioche Harrys Tranchée la recette Originale	18tranche	(link)
FERRERO ROCHER Boîte de 30	375 g, 30 pièces	(link)
Kiri® (32 % MG) à la crème de lait	240 g (12 Portions)	(link)
Bouchées de Poulet à la provençale	400 g (12 à 18 bouchées)	(link)
Thon entier au naturel	Poids net 190 g, poids net égoutté 140 g	(link)
Haricots beurre très fins	contenance : 4250ml, poids net total : 4000g, poids net égoutté : 2210g	(link)
Lentilles (Lot de 3 boîtes)	3 x [200 g (130 g net égoutté), 212 ml]	(link)
Délices du Potager - Mini poireaux	330 g (dont 180 g net), 370 mL	(link)
Chewing Gum Hollywood	28 g - 20 dragées	(link)
Fruit d'Or pro-activ® (35% MG) Tartine 260 g - Unilever	260 g (26 portions de 10 g)	(link)
Galettes, tout au beurre	130 g pour 20 galettes	(link)
Ketchup P'tits Heinz	280 ml - 310 g	(link)
Original Earl Grey	25 sachets	(link)
Cappellettis Tofu, Epinards Bio - 220 g - Céréal Bio	220 g (1 personne)	(link)
KUB ® Or	128 g (16 bâtonnets de 2 cubes)	(link)
Oeufs de poules Elevées en Plein Air (x 12) calibre Moyen - Carrefour	12 (calibre Moyen => 53 à 63 g)	(link)
Belvita sablé lait	8 sachets de 4	(link)
Escargots de Bourgogne Extra Gros - 400 g - E	400 g, 425 ml (3 douzaines)	(link)
nestle	228g (4x57g) / 48 cl (4x12cl)	(link)