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Python for Loops and while Loops Explained with Examples (range, break, continue)

P6.3 Loop Over Dictionaries and Use enumerate in Python

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Why. Prices by item, stock by warehouse — dictionary data needs looping too. And often you need a row number.

What. for k, v in d.items(): gives each key and value. for i, x in enumerate(list, 1): gives a counter and the item.

How.

Loop with two names

  1. Pick the right helper: .items() or enumerate().
  2. Write two names before in.
  3. Use both inside the block.

Worked example A — Stock by warehouse.

Step 1 — What we do. A logistics company has stock in three warehouses.

Step 2 — Type and run this code.

stock = {"Mumbai": 320, "Delhi": 150, "Chennai": 45}
for city, units in stock.items():
    print(city, units)

Step 3 — Output you should see.

Mumbai 320
Delhi 150
Chennai 45

Step 4 — What it means. Each loop gives one key (city) and its value (units).

Worked example B — Numbered list with enumerate.

Step 1 — What we do. We print a numbered top list of products.

Step 2 — Type and run this code.

products = ["Laptop", "Monitor", "Mouse"]
for i, p in enumerate(products, 1):
    print(f"{i}. {p}")

Step 3 — Output you should see.

1. Laptop
2. Monitor
3. Mouse

Step 4 — What it means. enumerate(..., 1) counts from 1. No manual counter needed.

Worked example C — Find low stock.

Step 1 — What we do. We flag warehouses with less than 100 units.

Step 2 — Type and run this code.

stock = {"Mumbai": 320, "Delhi": 150, "Chennai": 45}
for city, units in stock.items():
    if units < 100:
        print(f"Reorder for {city}: only {units} left")

Step 3 — Output you should see.

Reorder for Chennai: only 45 left

Step 4 — What it means. Loop plus if = a simple alert system.

Ravindra Bagale's Tip

Use enumerate instead of range(len(list)). It is shorter and avoids index mistakes.