Making techs unique to Civs?

[copedude]

Is their a way to make a technology only researchable by a certain Civ
eg. only America can research Americanism.
Also is their a way to make UUs and UBs unlockable.
eg. America makes marines and supermarkets until it researches Americanism and then can make SEALS and Malls
Note: I am completely new to Python so go easy on me if its easy

This may not be the place for this and if not I'll politely ask a mod to move it.
EDIT:Oh, Warlords and/or vanilla only please I don't have bts so it wouldnt help me much
EDIT:Just figured out the second problem still need help with the unique tech

 

[zyphyr]

Create a second tech, make it unresearchable (cost = -1).

Make the first require the second.

Give the second to America.