Split Into Multiples Lines has a real problem, which appears in the example code. Let say you have a long code block that includes the revised snippet: > quer

Split Into Multiples Lines has a real problem, which appears in the example code. Let say you have a long code block that includes the revised snippet: > query_params = s.split('?')[1].split('&')[-3:] > mylist = map(lambda x: x.split('=')[1], query_params) > ... > ... > (some more complex transformations, that only depends on mylist) When you're reading the later stages of the code, you still have to maintain a memory of what "query_params" does, even though it's no longer relevant. That actually increases the burden on your working memory. The one-liner is more complex to understand initially, but it self-documents that the only info that is relevant to the downstream is the result of the map(...). In general, the more variables that are declared in a code block, the more effort it is to understand, and the effect is probably superlinear with the number of variables. I'd say if you have to declare more than 5-6 variables, you should split into a separate function.