Question

Write a function def appendlist \((a, b)\) that appends one list after another. For example, if a is \(\begin{array}{lll}1 & 49 & 16\end{array}\) and \(\mathrm{b}\) is \(\begin{array}{lllll}9 & 7 & 4 & 9 & 11\end{array}\) then append returns a new list containing the values \(\begin{array}{lllllllll}1 & 4 & 9 & 16 & 9 & 7 & 4 & 9 & 11\end{array}\)

Short answer

Define a function that concatenates two lists and returns the result.

Step-by-step solution

Define the Function

Start defining the function with the name `appendlist` that accepts two parameters, `a` and `b`. This function will combine these two lists as specified.

Combine Lists Using Concatenation

Use the list concatenation operation in Python. This can be done by using the `+` operator, which will append list `b` to the end of list `a`. It's simple and efficient for our purpose.

Return the Combined List

Once the lists are concatenated, the function should return the new combined list. This involves using the `return` statement to output the concatenated result.

Example

For example, if `a = [1, 49, 16]` and `b = [9, 7, 4, 9, 11]`, the function will return `[1, 49, 16, 9, 7, 4, 9, 11]`.

Key concepts

List Concatenation

In Python, list concatenation is a straightforward operation that involves joining two or more lists into one continuous list. It's analogous to simply adding items from one list directly to the end of another list, just like connecting pieces of a puzzle. To concatenate lists, you use the `+` operator. This operator takes two lists and creates a new list that begins with the elements of the first list followed by the elements of the second list. This can be particularly useful when you want to consolidate data without adjusting the elements of existing lists.

• List `a` and list `b` can seamlessly merge into a new list as `[a] + [b]`.
• The original lists remain unchanged, which means you always have the original data available.
• The efficiency of this operation is suitable for moderate-sized lists, but be cautious with very large data sets as it may affect memory and performance.

Function Definition

Defining a function in Python is the groundwork for creating reusable code snippets that perform specific tasks. A function allows you to structure your code more efficiently. It acts like a little tool that you can call whenever you need to execute a particular action. The process starts with the `def` keyword, followed by the function name and parentheses. Inside the parentheses, you can specify parameters that the function requires to operate. In this exercise, the function is defined as `def appendlist(a, b):` where `appendlist` is the function name and `a`, `b` are the parameters expected to be passed as arguments.

• Function names should be descriptive to clearly indicate the action performed.
• Parameters act as placeholders for the actual data values provided when the function is called.
• Organizing code into functions can improve clarity and prevent redundancy in code writing.

Return Statement

In Python, the `return` statement is critical within a function. It determines what the function outputs once it has completed its operation. After processing the input data, if you want to provide a result back to the part of the program that called the function, you use a `return` statement followed by the value to be sent back. It concludes the function execution and specifies the data to be "returned." Without a `return` statement (or an implicit return with no value, which returns `None`), the function won’t output any value. In `appendlist`, the `return` statement conveys the final concatenated list from the function back to the caller.

• Placement of the `return` statement is strategic to ensure the function has completed its intended task.
• Using `return` allows for the function to provide different results based on dynamic input.
• A `return` can send back any data type, like integers, strings, lists, etc., offering flexibility in function design.