On 27/05/18 01:19, Mike McClain wrote: > In their discussion of 'List replication operator' > Steven D'Aprano and Ben Finney used these '_' and '__'. > Steve said, "[[] for _ in range(5)]". > Ben said, "[ [] for __ in range(5) ]". > > These aren't listed separately in the index, where might I find > written discussion of these?
There's nothing special about _, it's just a possible name of a variable, albeit a very short and entirely uninformative one. Normally, it's not something you'd actually want to name a variable, of course. As such, _ has become an idiomatic name for dummy variables, i.e. something you use when syntax requires you to give a variable name, but you don't actually want one (probably because you're throwing the variable away). This mostly happens in generator expressions/list comprehensions. -- Thomas -- https://mail.python.org/mailman/listinfo/python-list
