lambda function is JUST LIKE ANY FUNCTION.  Except you define it differently; instead of "def", you do a variable assignment.

Partial is something different.  It basically creates a new function, by packaging an existing function "F" with some of the parameters already.  So if "F" takes 3 parameters (a,b,c), you can use partial to define a new function (G) that calls "F" with b=2 and c=1.  So G only would take 1 parameter (a), and call F with a (from G), b=2, c=1.

So, partial is just a convenient repackaging / renaming / shortcut thing.