Loops are a commonly used structure in programming that allows you to repeat a block of code a set number of times, or until you meet a particular condition. This is useful for many reasons. For ...

In the following example, we loop through a list of numbers, and use the variable digit to hold each number in turn: Strings in Python are considered “sequences” — they can be iterated over, and the ...

A behind-the-scenes blog about research methods at Pew Research Center. For our latest findings, visit pewresearch.org. Identifying causal relationships from observational data is not easy. Still, ...