refactor code to split into functions + preliminary regex for ingredient extraction

src/db.py

@@ -1,3 +1,4 @@
+from typing import Text
 from sqlalchemy import create_engine, Column, Integer, String, \
                       ForeignKey, UniqueConstraint
 from sqlalchemy.engine import URL
@@ -40,6 +41,16 @@ class RecipeIngredient(Base):
     text = Column(String, nullable = False)
     recipe_id = Column(Integer, ForeignKey('Recipe.id'))
     ingredient_id = Column(Integer, ForeignKey("Ingredient.id"))
+
+class RecipeIngredientParts(Base):
+    __tablename__ = 'RecipeIngredientParts'
+    
+    id = Column(Integer, ForeignKey("RecipeIngredient.id"), primary_key=True)
+    quantity = Column(String)
+    unit = Column(String)
+    ingredient = Column(String)
+    supplement = Column(String)
+
     
 
 def get_engine(use_dotenv = True, **kargs):

src/scrape.py

@@ -1,11 +1,88 @@
 import db
+import re
 from sqlalchemy import select, desc
+from sqlalchemy.exc import IntegrityError
 from sqlalchemy.orm import sessionmaker
 import bs4
 from urllib.request import urlopen
+from urllib.parse import urljoin
 import logging
 from argparse import ArgumentParser
 
+def parse_ingredient(ingredient_text):
+    units = ['teaspoon', 'tablespoon', 'gram', 'once', 'jar', 'cup', 'pinch']
+    number_regex = '((?:[\d\\u00BC-\\u00BE\\u2150-\\u215E]*\s?(?:\(.+\))?)*)'
+    ingredient_regex = '([a-zA-Z \'\-]+)'
+    supplement_regex = ',?(.*)'
+    units_regex = "|".join([f'[{unit[0]}{unit[0].capitalize()}]{unit[1:]}' 
+                            for unit in units])
+    units_regex = f"((?:{units_regex})[s]?)"
+    
+    regex = re.compile(number_regex + 
+                       units_regex + 
+                       ingredient_regex + 
+                       supplement_regex)
+    
+    m = regex.match(ingredient_text)
+    logging.info(f"Parsed {ingredient_text}, found: {m}")
+    if not m:
+        return None
+
+    return [text.strip() for text in m.groups()]
+
+def load_recipe(recipe_url):
+    try:    
+        logging.info(f'Loading Recipe: {recipe_url}')
+        with urlopen(recipe_url) as f:
+            if f.getcode() == 404:
+                raise Exception(f"Recipe Does not exist: {recipe_url}")
+            return bs4.BeautifulSoup(f.read().decode(), 'html.parser')
+
+    except Exception as e:
+        logging.warning(f"Could not download or parse recipe: {recipe_url}")
+        logging.warning(e)
+
+    return None
+
+def parse_recipe(session, recipe, site):
+    recipe_url = urljoin(site.base_url, str(recipe.identifier))
+    recipe_page = load_recipe(recipe_url)
+    if not recipe_page:
+        return None
+
+    name_candidates = recipe_page.find_all(class_=site.name_class)
+    if len(name_candidates) == 0:
+        raise Exception(f"Could not extract recipe name: {recipe_url}")
+    name_div = name_candidates[0]
+    recipe.name = name_div.text
+
+    logging.info(f"Adding Recipe {recipe}")   
+
+    session.add(recipe)
+    session.flush()
+
+    ingred_candidates = recipe_page.find_all(class_=site.ingredient_class)
+    for candidate in ingred_candidates:
+        ingred = db.RecipeIngredient(text=candidate.text,
+                                         recipe_id=recipe.id)
+        session.add(ingred)  
+        session.flush()
+                           
+        parts = parse_ingredient(ingred.text)
+        if parts:
+            quantity, unit, ingredient, supplement = parts
+            ingred_parts = db.RecipeIngredientParts(id = ingred.id,
+                                                 quantity = quantity,
+                                                 unit = unit,
+                                                 ingredient = ingredient,
+                                                 supplement = supplement)
+            session.add(ingred_parts)
+        
+    logging.info(f"{len(ingred_candidates)} ingredients found. Inserting into DB")
+
+    return recipe
+    
+
 parser = ArgumentParser(description="Scrape a recipe site for recipies")
 parser.add_argument('site',
                     help='Name of site')
@@ -41,44 +118,26 @@ with S.begin() as sess:
                             scalar()
             starting_id = int(last_recipe.identifier) + 1
         else:
-            starting_id = args.id
+            starting_id = int(args.id)
         recipe_ids = range(starting_id, starting_id+int(args.n))
         logging.info(f'Retreving {args.n} recipes from {site.base_url} starting at {starting_id}')
     
     
-        
+    
     for recipe_id in recipe_ids:            
-        recipe = db.Recipe(identifier = recipe_id, recipe_site_id = site.id)
+        try: 
+            savepoint = sess.begin_nested()
 
-        recipe_url = f'{site.base_url}/{recipe.identifier}'
-        logging.info(f'Loading Recipe: {recipe_url}')
-        try:
-            with urlopen(recipe_url) as f:
-                if f.getcode() == 404:
-                    raise Exception(f"Recipe Does not exist: {recipe_url}")
-                recipe_page = bs4.BeautifulSoup(f.read().decode())
-    
-    
-            name_candidates = recipe_page.find_all(class_=site.name_class)
-            if len(name_candidates) == 0:
-                raise Exception(f"Could not extract recipe name: {recipe_url}")
-            name_div = name_candidates[0]
+            recipe = db.Recipe(identifier = recipe_id, recipe_site_id = site.id)
+            parse_recipe(sess, recipe, site)
+
+            savepoint.commit()
+        except KeyboardInterrupt as e:
+            savepoint.rollback()
+            break
         except Exception as e:
-            logging.warning(f"Could not download or parse recipe: {recipe_url}")
-            logging.warning(e)
-            continue
-            
-        recipe.name = name_div.text
-        logging.info(f"Adding Recipe {recipe}")   
+            savepoint.rollback()
+            logging.error(e)
+            break
 
-        sess.add(recipe)
-        sess.flush()
-
-        ingredients = []
-        ingred_candidates = recipe_page.find_all(class_=site.ingredient_class)
-        for ingredient in ingred_candidates:
-            ingredients.append(db.RecipeIngredient(text=ingredient.text,
-                                                recipe_id=recipe.id))
-            
-        logging.info(f"{len(ingredients)} ingredients found. Inserting into DB")
-        sess.add_all(ingredients)
+