Python Program to Generate Random Number in Range

Use import random and then random.randint(start, end) to generate a random number between start and end inclusive.

Examples

Inputstart=1, end=10

OutputRandom number between 1 and 10, e.g., 7

Inputstart=0, end=0

Output0

Inputstart=100, end=105

OutputRandom number between 100 and 105, e.g., 103

How to Think About It

To generate a random number in a range, first decide the start and end values. Then use a built-in tool that picks a number randomly between those two values, including both ends.

Algorithm

1

Import the random number module.

2

Set the start and end values for the range.

3

Use the function to get a random number between start and end.

4

Print or return the random number.

Code

python

import random

start = 1
end = 10
random_number = random.randint(start, end)
print(f"Random number between {start} and {end}: {random_number}")

Output

Random number between 1 and 10: 7

Dry Run

Let's trace generating a random number between 1 and 10 through the code

1

Import random module

random module is ready to use

2

Set start and end

start = 1, end = 10

3

Generate random number

random.randint(1, 10) returns 7 (example)

4

Print result

Output: Random number between 1 and 10: 7

Step	Action	Value
1	Import random	Module ready
2	Set range	start=1, end=10
3	Generate number	7
4	Print output	Random number between 1 and 10: 7

Why This Works

Step 1: Import random module

The random module has functions to create random numbers.

Step 2: Use randint function

random.randint(start, end) picks a random integer including both start and end.

Step 3: Print the result

We show the random number so you can see the output.

Alternative Approaches

random.randrange()

python

import random
start = 1
end = 10
random_number = random.randrange(start, end + 1)
print(f"Random number between {start} and {end}: {random_number}")

Works like randint but excludes the end value, so we add 1 to include it.

random.uniform() for float

python

import random
start = 1.0
end = 10.0
random_number = random.uniform(start, end)
print(f"Random float between {start} and {end}: {random_number}")

Generates a random floating-point number instead of an integer.

Complexity: O(1) time, O(1) space

Time Complexity

Generating a random number is a constant time operation with no loops.

Space Complexity

Only a few variables are used, so constant space.

Which Approach is Fastest?

random.randint and random.randrange are equally fast; random.uniform is for floats and slightly different use.

Approach	Time	Space	Best For
random.randint	O(1)	O(1)	Random integer including both ends
random.randrange	O(1)	O(1)	Random integer excluding end (adjustable)
random.uniform	O(1)	O(1)	Random floating-point numbers