For what it's worth, PyCharm (and I assume the other IntelliJ IDE's) has added zero-latency typing [0 (that blog post mentions rolling out the feature in an Early Access build, but given semantic highlighting is in normal Pycharm now, I would imagine zero-latency input is as well).

0: https://blog.jetbrains.com/pycharm/2016/12/pycharm-2017-1-ea...