In computer programming, an **iterable** object is a collection of items that can be processed one at a time. Essentially, it's anything you can loop through, accessing each element sequentially. This concept is fundamental to many programming languages, enabling efficient data manipulation and processing. Iterables often provide an iterator, which handles the step-by-step access of the elements. The order of iteration may be explicitly defined or implicit, depending on the data structure.
Iterable meaning with examples
- In Python, lists, tuples, dictionaries, and strings are all iterable. You can easily use a 'for' loop to iterate through each element. For example, a list of numbers can be easily added, or a string can be used to count the number of characters. The 'for' loop is one of the primary ways to do so, but the iterator also handles this under the hood.
- Imagine you have a file containing multiple lines of text. This file, if handled correctly by the program, could be considered an iterable, where each line represents an item. You might iterate through the lines to search for a specific keyword, extracting the relevant information from each line. The program reads each line until the end of the file.
- Consider a database query that returns multiple rows of results. This result set can often function as an iterable. A programmer can then iterate through the query, processing each row individually to construct an application, showing the results of the query. The result set is not a single item, but a list of items to handle, which is the key to this example.
- Even the range function (e.g., range(1, 11)) is an iterable. It produces a sequence of numbers that can be processed one by one, as if they exist. This iterable is often used in loops to repeat a block of code a specific number of times. The range function can be useful when you need to provide a numbered list, but is not as useful if no numbers are required.