3. You work on a project where local coding style mandates that lambda is spelled λ.  In this case, there will be plenty of places in the code base to copy and paste λ from. (In the worst case you copy and paste it from the coding style manual.)  More likely, however, the project that requires λ would have a precommit hook that translates lambda to λ in all new code and you can continue using the 6-character keyword in your input.

That this your solution makes the proposoal a -100 and if you're going to implement a precommit hook to convert lambda to λ you might has well implement a custom coding that supports λ (like pyxl does for html\xml tags). Python isn't and shouldn't be APL.