Convert ["NA", "N/A"] to null?
Created by: onyxfish
Useful for datasets like this (see Appointment column): http://data.cityofchicago.org/Government/Public-Technology-Resources/nen3-vcxj
Created by: onyxfish
Useful for datasets like this (see Appointment column): http://data.cityofchicago.org/Government/Public-Technology-Resources/nen3-vcxj