Products quantities
How to handle it
Logic to handle it
Existing libraries to parse weights and quantities
Using Wikidata
- Translations and aliases of units
- weight unit list
- units of volume
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
Canonical approach
The real-world quantities for products as used by the user (and printed on the packages) is not ideal. It is often impossible to parse the quantities and understand what is indicated. However it is possible to find some common approach. This is a first attempt.
Some remarks:
- product central - any quantity that is indicated is about the product and not the packaging;
- product unit - reference may be made to a product unit, eg a cookie, a chocolate egg, etc.
- equivalents - one or more equivalents might be available, i.e. in grams, oz or liters, 24 cookies / 6 cookies in 4 packages;
- containers - the generic toplevel package is a container;
- subcontainers - a container might comprise multiple subcontainers (or even subsubcontainers) [hierarchy?/taxonomy?]
- (sub-)container synonyms - a user might container other words to describe a container, such as bottle, can, bag, etc. [hierarchy?/taxonomy?]
- defaults - in indicating the quantity some parts are assumed to be understood. If it states 33cl it is assumed to be about the container (the bottle) and the product (beer);
- components - a product might consist of multiple components, which must be combined to get the product. Cf Creme brulee = vanilla cream + caramel flakes (to be heated).
- subproduct - sometimes a subproduct quantity is indicated (net/brut, egoutté/drained);
- verbosity - the language used in specifying quantity must be translated to a parsable format;
- scattered - all information necessary to fill the entire quantity formula might be scattered over the package.
- detail quantities - sometimes a detailed quantity might be present (1 biscuit weighs 23g) and a multiplier is needed to get the total weight of the package;
- marketing - some quantities are added for marketing purposes, extra 25g;
- subsubcontainers - an extra subdivision, eg 1 carton of yoghurt with 2 layers and 8 pots per layer;
- servings - a quantity might contain a number of servings
Generic formula
Any generic quantity formula should reference the product(-name), the container and a volume or weight measure. The productname and container should (?) reference the corresponding fields.
The quantity formula is:
container_multiplier x container_name x product_multiplier x (sub_)product_name x quantity_value x quantity_unit
This formula should be valid for each container/subcontainer/subsubcontainer level, but should reflect the entire package. So one has to add multipliers and brackets where appropriate.
For example:
- 1 bottle of red wine comprising 70 cl (on the bottle indicated as "70 cl");
- 1 package of granola cookies with a total weight of 276 g (just printed as 276g), which is equivalent to:
- 1 package of 12 biscuits with a total weight of 276g, which is equivalent to:
- 1 package of 12 biscuits with an individual weight of 23g per biscuit.
Practical usage
In practice however other indications are used by users. There is no best practice defined.
- to indicate times, either a "*" or a "x" is used;
- equivalent formulas are distinguished by a ";" or brackets "(,)"
- 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.
Test approach
To test this approach the examples found in France have translated to this formal approach:
| Quantity as stated by user | Container multiplier | Container name | Product multiplier | Product name | Quantity value | Quantity unit |
|---|---|---|---|---|---|---|
| 1 kg (8 pots) - [2 x (4 x 125 g)] | 8 | pots | - | - | 1 | kg |
| or | 2 x 4 | pots | - | - | 125 | g |
| 275 g [250 g + 25 g (10 %) gratuit] | - | - | - | - | 275 | g |
| or | - | - | - | - | 275 + 25 | g |
| 2 * 400 g (800 g) | 2 | - | - | - | 400 | g |
| or | - | - | - | - | 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] | - | - | - | - | 200 | g |
| or | - | - | 2x8 | mini-nems | 160 | g |
| + | - | - | - | sauce nuoc mâm | 40 | g |
| 211,5 g (9x23,5g) | - | - | - | - | 211,5 | g |
| or | 9 | - | - | - | 23,5 | g |
| 220g (2 unités, 2 x (60 g + 50 g)) | - | - | - | - | 220 | g |
| or | - | - | 2 | unités | 60 + 50 | g |
| 2 x 21.5 g = 43 g | - | - | - | - | 43 | g |
| or | 2 | - | - | - | 21.5 | g |
| 300 g (15 biscuits de 20 g) | - | - | - | - | 300 | g |
| or | - | - | 15 | biscuits | 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 ) | - | - | - | - | 400 | g |
| or | - | - | 12 à 18 | bouchées | - | - |
| Poids net 190 g, poids net égoutté 140 g | - | - | - | net | 190 | g |
| Poids net 190 g, poids net égoutté 140 g | - | - | - | net égoutté | 140 | g |
| contenance : 4250ml, poids net total : 4000g, poids net égoutté : 2210g | - | - | - | - | 4250 | ml |
| or | - | - | - | net | 4000 | g |
| or | - | - | - | net égoutté | 2210 | g |
| 3 x [200 g (130 g net égoutté), 212 ml] | ||||||
| 330 g (dont 180 g net), 370 mL | - | - | - | - | 330 | g |
| 330 g (dont 180 g net), 370 mL | - | - | - | - | 370 | mL |
| 330 g (dont 180 g net), 370 mL | - | - | - | net | 180 | g |
| 28 g - 20 dragées | - | - | 20 | dragées | 28 | g |
| 260 g (26 portions de 10 g) | - | - | - | - | 260 | g |
| 130 g pour 20 galettes | - | 130 | g | - | ||
| or | 20 | - | - | galettes | ||
| 280 ml - 310 g | - | 280 | ml | - | ||
| - | 310 | g | - | |||
| 25 sachets | 25 | - | - | sachets | ||
| 220 g (1 personne) | - | 220 | g | - | ||
| 128 g (16 bâtonnets de 2 cubes) | - | 128 | g | - | ||
| 16 | - | - | bâtonnets | |||
| 16x4 | - | - | cubes | |||
| 12 (calibre Moyen => 53 à 63 g) | 12 | - | - | calibre moyen | ||
| 8 sachets de 4 | 8 | - | - | sachets | ||
| 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) |