Party Provisioner 🎉

"How much should I buy?" — the question every host asks, usually answered by panic-buying 30% too much or running dry at hour two. This skill computes provisioning from the four variables that actually matter: how many guests, how long, what mix of drinkers/eaters, how hot is it — using the same per-guest-hour arithmetic bartenders and caterers use.

Overview

The core unit is the guest-hour: a guest consumes X units per hour, so a 4-hour party for 20 is 80 guest-hours regardless of how you slice it. scripts/party_planner.py implements:

Drinks (a "drink" = 1 beer / 1 glass of wine / 1 cocktail-served shot)

• Baseline: 2 drinks in the first hour, 1 per hour after (industry standard)
• Adjustments: heat (+20%), dancing/active event (+10%), light drinkers (−20%), wine-only crowd (1.5 glasses/hr)
• Mix split: from drinker preferences (e.g. 40/40/20 beer/wine/spirits)
• Units out: beer bottles, wine bottles (5 glasses each), 750ml spirit bottles (17 shots), mixers, plus water/soda for non-drinkers & hydrating drinkers
• Round-up rules so you don't buy 0.8 bottles

Ice: 1.5 lb per drinking guest-hour + 1 lb per bag cooler + bar ice for chilling bottles (formula from catering guides: ~1 lb/person for the evening + chilling needs)

Food (per guest-hour, catering norms):

• Meal party: 1.2 lb total food/person for a 2-3h dinner
• Appetizer party: 12 bites/hour/person
• BBQ: ½ lb protein/person/meal (⅓ lb sides)
• Kids count ½, big eaters 1.5×

Extras: glassware (2 per guest, or 1 + rotates), plates ×1.5 servings, napkins ×3, cups, trash bags, tables/chairs per seating standards

When to Use

• "I'm hosting 25 people Saturday night — how much wine and beer?"
• "Backyard BBQ for 40, kids included, how many burgers and how much ice?"
• "Wedding reception, 80 guests, 5 hours, beer/wine only"
• "How many bottles of prosecco for a 3-hour brunch for 15?"
• "Cocktail party, no dinner — how many appetizers?"

Don't use for: commercial/cash-bar operations (licensing, stock management), huge catered events with pro event planners (they have vendor math), or dietary-restriction menu design (different problem).

How It Works — Steps

1. Headline numbers:

   python3 scripts/party_planner.py --guests 25 --hours 4 --style cocktail
   

2. Refine the crowd:

   python3 scripts/party_planner.py --guests 40 --hours 5 --style bbq \
     --drinkers 30 --kids 10 --heat --mix 40/40/20
   

3. Read the shopping list — bottles, lbs, bites, and units to actually buy (with round-up), grouped by store section.
4. Budget check — enter unit prices (--price-beer 1.2) for a cost estimate per category and total.
5. Print the host card — ratios to remember, timing notes (what to chill when), and the "running low?" tripwires.

Consumption Model (per drinking guest)

drinks(guest) = 2 × adj_first_hour + adj_1_per_subsequent_hour
adj = base × heat(1.2 if >27°C) × active(1.1) × light(0.8)
non-drinkers: 2 non-alc drinks/hr (soda/water/coffee-tea)

Wine-only event: 1.5 glasses/hr flat. Champagne toast: +1 glass/guest.

Worked Example

40 guests (30 drinkers, 10 kids), 5h BBQ, hot day, mix 40/40/20:
  guest-hours: 150 drinker-hours → base drinks = 2+4 = 6/drinker
  heat adj ×1.2 → 7.2 drinks × 30 drinkers = 216 drinks
  split: 86 beer + 87 wine glasses + 43 cocktails
  BUY: 90 beer bottles · 18 wine bottles · 3×750ml spirits · 43 mixer-servings
  non-alc: 300 servings (200 sodas + 100 water/coffee)
  ICE: 3 × 20lb bags minimum (plus chilling)
  FOOD: 12.5 lb protein + sides + kid adjustments
  extras: 80 cups, 60 plates, 180 napkins, 4-5 trash bags

Common Pitfalls

1. Sizing by "drinks per person" without duration. A 2-hour dinner and a 6-hour party are different planets — always guest-×-hours.
2. Forgetting non-drinkers get thirsty too. Budget 2 non-alc drinks/hour/guest — running out of water is the #1 real-party failure, and on a hot day it's a safety issue.
3. Wine bottle math — a 750ml bottle is 5 glasses, not 4 (poured at 150ml catering standard). Underestimating here runs dry in hour one.
4. Ice melts. Bagged ice for coolers needs ~1 lb/person extra; crushed bar ice for cocktails melts ~30% faster. Buy more than the formula if it's >27°C.
5. Kids eat half but drink like adults (of non-alc). Count them in drinks, halve them in food.
6. No round-up = buying 0.8 bottles. The tool rounds beer to 6-packs, wine to bottles, spirits to 750ml — keep that.
7. Champagne "toast inflation": a toast pour is 100ml, not a full glass — 8 glasses/bottle for toast purposes.

Verification Checklist

• Drinks ÷ drinkers falls in 0.8–2.5/hour band (sanity)
• Non-alc servings ≥ 1.5 × guest-hours
• Ice ≥ 1 lb × drinking guests for the evening (plus cooler ice)
• Every buy-line is a whole purchasable unit
• Water available matches heat adjustment (hot day → +20% everything)

One-Shot Recipes

Dinner party, 8 friends, 3 hours, wine-forward:

python3 scripts/party_planner.py -g 8 -t 3 --style dinner --mix 20/60/20

Wedding, 80 guests, 5h, beer & wine only, champagne toast:

python3 scripts/party_planner.py -g 80 -t 5 --style reception --drinkers 60 \
  --mix 50/50/0 --toast

Kid birthday, zero alcohol focus:

python3 scripts/party_planner.py -g 20 -t 3 --style birthday --kids 12 --drinkers 0