> * Types are expensive and dont tend to pay off on spikey/experimental/MVP code, most of which gets thrown away.
Press "X" to doubt. Types help _a_ _lot_ by providing autocomplete, inspections, and helping with finding errors while you're typing.
This significantly improves the iteration speed, as you don't need to run the code to detect that you mistyped a varible somewhere.
Pycharm, pyflakes, et all can do most of these without written types.
The more interesting questions, like “should I use itertools or collections?” Autocomplete can’t help with.