Day 21: Allergen Assessment

Classes:

Identifier(value)	Represent an ingredient or allergen identifier.
Allergen(value)	Represent an identifier of an allergen.
Ingredient(value)	Represent an identifier of an ingredient.
IngredientLine(line)	Specify a well-formed line representing an ingredient list with the allergen.
Entry(ingredients, allergens)	Represent an entry in the list of foods.

Data:

INGREDIENT_LINE_RE

Express a line specifying an ingredient list along with the allergens.

Functions:

parse_ingredient_line(line)	Encapsulate the parsing of line into entries.
serialize_entry(entry)	Serialize the entry back into the string.
find_non_allergenic_ingredients(entries)	Find the ingredients without allergens.
solve(lines)	Parse the input and return the set of ingredients without allergens.

class Identifier(value: str)

Represent an ingredient or allergen identifier.

Methods:

__new__(cls, value)

Enforce the properties on the identifier.

static __new__(cls, value: str) → Identifier

Enforce the properties on the identifier.

Requires

• re.fullmatch(r"^[a-zA-Z]+Z", value)

class Allergen(value: str)

Represent an identifier of an allergen.

class Ingredient(value: str)

Represent an identifier of an ingredient.

INGREDIENT_LINE_RE = re.compile('\\s*(?P<ingredients>[a-zA-Z]+(\\s+[a-zA-Z]+)*)\\s+\\(contains\\s+(?P<allergens>[a-zA-Z]+(\\s*,\\s*[a-zA-Z]+)*)\\)')

Express a line specifying an ingredient list along with the allergens.

class IngredientLine(line: str)

Specify a well-formed line representing an ingredient list with the allergen.

Methods:

__new__(cls, line)

requires

static __new__(cls, line: str) → IngredientLine

Requires

• INGREDIENT_LINE_RE.fullmatch(line)

class Entry(ingredients: List[Ingredient], allergens: List[Allergen])

Represent an entry in the list of foods.

Methods:

__init__(ingredients, allergens)

Initialize with the given values.

Attributes:

ingredients	Ingredients of the entry
allergens	Allergens of the entry

__init__(ingredients: List[Ingredient], allergens: List[Allergen]) → None

Initialize with the given values.

Requires

• len(ingredients) > 0

• len(allergens) > 0

ingredients: List[Ingredient]

Ingredients of the entry

allergens: List[Allergen]

Allergens of the entry

parse_ingredient_line(line: IngredientLine) → Entry

Encapsulate the parsing of line into entries.

serialize_entry(entry: Entry) → IngredientLine

Serialize the entry back into the string.

Ensures

• result == serialize_entry(parse_ingredient_line(result))

find_non_allergenic_ingredients(entries: List[Entry]) → Set[Ingredient]

Find the ingredients without allergens.

solve(lines: List[IngredientLine]) → Set[Ingredient]

Parse the input and return the set of ingredients without allergens.