Loading...
Loading...
Generate sequences of numbers with range()
range() generates a sequence of numbers — perfect for when you need to repeat something a specific number of times, or count through a range of numbers.
for i in range(5):
print(i) # 0, 1, 2, 3, 4
for i in range(2, 6):
print(i) # 2, 3, 4, 5
for i in range(0, 10, 2):
print(i) # 0, 2, 4, 6, 8| Call | Generates |
|---|---|
| `range(stop)` | 0, 1, 2, ..., stop-1 |
| `range(start, stop)` | start, start+1, ..., stop-1 |
| `range(start, stop, step)` | start, start+step, start+2*step, ... |
for i in range(3):
print(f"Round {i + 1}")Output:
Round 1
Round 2
Round 3Step by step:
# Count from 1 to 5
for i in range(1, 6):
print(i) # 1, 2, 3, 4, 5
# Count backward
for i in range(10, 0, -1):
print(i) # 10, 9, 8, ..., 1
print("Blast off! 🚀")
# Use i to access list items by index
colors = ["red", "green", "blue"]
for i in range(len(colors)):
print(f"Color {i}: {colors[i]}")| ❌ Wrong | Why | ✅ Right |
|---|---|---|
| `range(5)` expecting `1, 2, 3, 4, 5` | Starts at 0 by default | `range(1, 6)` |
| `range(1, 5)` expecting 5 items | Stop is exclusive — only 1, 2, 3, 4 | `range(1, 6)` |
| `range(10, 0)` | Start < stop with default step=1 = empty | `range(10, 0, -1)` |
| `for i in range(len(list)):` when values alone suffice | Overly complex | `for item in list:` |
Write a program that:
print("1 to 10:")
for i in range(1, 11):
print(i)
print("Even numbers 2-20:")
for i in range(2, 21, 2):
print(i)
print("Multiples of 5:")
for i in range(5, 51, 5):
print(i)