What is a concise way to create lists using an expression for each item in an iterable?

What is a concise way to create lists using an expression for each item in an iterable?

• A. list comprehensions
• B. list generators
• C. array comprehensions
• D. set builders

Answer: (A)

The correct answer is list comprehensions. This is a powerful feature in Python that allows you to create a new list by applying an expression to each item in an iterable (such as a list or a range) in a single, concise line of code. The syntax typically involves specifying the expression followed by a `for` clause and, optionally, additional `if` clauses to filter the items included in the new list. For example, using a list comprehension, you can easily create a list of squares for the numbers in a given range: ```python squares = [x**2 for x in range(10)] ``` This approach is not only succinct but also enhances readability compared to creating a list using traditional loops. The other options mentioned don't fit this description of creating lists in the same way; for instance, while list generators are a common term, they primarily refer to generator expressions, which produce generators rather than lists. Array comprehensions and set builders are also different constructs that serve other purposes in Python.

The correct answer is list comprehensions. This is a powerful feature in Python that allows you to create a new list by applying an expression to each item in an iterable (such as a list or a range) in a single, concise line of code. The syntax typically involves specifying the expression followed by a for clause and, optionally, additional if clauses to filter the items included in the new list.

For example, using a list comprehension, you can easily create a list of squares for the numbers in a given range:

squares = [x**2 for x in range(10)]

This approach is not only succinct but also enhances readability compared to creating a list using traditional loops. The other options mentioned don't fit this description of creating lists in the same way; for instance, while list generators are a common term, they primarily refer to generator expressions, which produce generators rather than lists. Array comprehensions and set builders are also different constructs that serve other purposes in Python.