Question

Write a loop that fills a list values with ten random numbers between 1 and 100 . Write code for two nested loops that fill values with ten different random numbers between 1 and 100 .

Short answer

Use nested loops: the outer loop adds numbers until 10 are unique, while the inner loop checks for duplicates.

Step-by-step solution

Import necessary modules

First, we need to import the 'random' module, as it contains the functions required to generate random numbers.

Create the outer loop for generating random numbers

Initialize an empty list called `values`. Use a `while` loop to keep adding random numbers to `values` until it has 10 numbers.

Generate random number

Within the `while` loop, use `random.randint(1, 100)` to generate a random number between 1 and 100. Append this number to the list `values` if certain conditions are met.

Ensure uniqueness of numbers

In the nested loop, check if the generated random number is already in the `values` list. If not, append the number to `values`; otherwise, continue generating a new number until a unique one is found to add.

Exit condition

The outer loop continues until the `values` list contains exactly 10 numbers. Since each number must be unique, check this length condition to terminate the loop.

Print the final list

Once the loop terminates, print the `values` list to verify it contains 10 unique random numbers between 1 and 100.

Key concepts

Random Number Generation

Random number generation is a fundamental tool in programming, frequently used for simulations, games, and testing. In Python, the 'random' module provides various functions to generate random numbers conveniently. One of the most popular choices for generating an integer within a specific range is `random.randint(a, b)`, where `a` is the starting point and `b` is the endpoint of your intended range. This function returns a random integer, where both `a` and `b` are inclusive. To employ this functionality, you first need to import the `random` module. For example: ```python import random random_number = random.randint(1, 100) ``` This code will give you a random number from 1 to 100 each time it's executed. The outcome varies with each call. This randomness provides a way to simulate unpredictability in programs, serving as a valuable resource for developers.

Loops in Python

Loops are essential in automating repetitive tasks. Python offers two primary looping constructs: `for` loop and `while` loop. Each loop type serves different purposes based on the complexity and requirements of the task. 1. **`For` loop**: Ideal for iterating over a sequence whenever you know the number of iterations beforehand. 2. **`While` loop**: Useful for when the number of iterations isn't fixed, and the loop depends on a condition being true. In the context of generating random numbers until a list reaches a certain size, a `while` loop is apt. It allows the loop to continue until the list contains exactly ten numbers, checking the list's length after each addition to decide whether to keep looping.

List Manipulation

Lists are versatile data structures in Python, enabling the collection and organization of items. Through list manipulation, we can effectively manage these items. - **Appending Items**: Use `list.append(element)` to add an element to the end of a list. - **Checking List Size**: Employ `len(list)` to get the current size of the list, which helps in loop termination conditions. - **Membership Testing**: To check if an item exists within a list, use the `in` keyword to test membership efficiently. For example: ```python values = [] if random_number not in values: values.append(random_number) ``` This snippet helps maintain a list of unique random numbers, checking each potential new number against existing ones.

Nested Loops

Nested loops are a technique where one loop operates inside another. This setup is especially useful for situations requiring multiple levels of iteration. In this exercise, nested loops ensure uniqueness in your list of random numbers. The outer loop generates numbers and handles the size requirements, while an inner loop ensures numbers are unique by checking the current list. - **Outer Loop**: Continues generating random numbers until the list is complete. - **Inner Loop**: Verifies each number is not already in the list, maintaining uniqueness. Implementing nested loops effectively: ```python while len(values) < 10: num = random.randint(1, 100) if num not in values: values.append(num) ``` This structure helps automate complex problems by breaking them into smaller, manageable tasks with nested logic.