> Also, naming something implies it will be useful in another context, which one-off lambdas rarely are. Not necessarily. I find it helps readability to do thi

> Also, naming something implies it will be useful in another context, which one-off lambdas rarely are. Not necessarily. I find it helps readability to do this: def prunde_indices(indices, cutoff): def match_old_index(index): return index.timestamp < cutoff old_indices = filter(match_old_index, indices) # ... do things with old_indices as opposed to using an anonymous lambda. That doesn't mean I have to reuse it outside of this function.