BBQLS1, it doesn't matter. However, two or three shots can seriously deteriorate the appearance of a purse, although it's quicker than fumbling around to draw the handgun from the purse before doing Good Things to Bad Guys.. Stuff spills out, also. They sell purses at Wal*Mart, though. I've seen 'em.
Hammer or hammerless, it's not unwise to put the handgun in a thin sandwich baggie for purse carry. The problem is not the hammer; it's junk protruding into the trigger guard. The baggie solves that problem, but won't interfere with pulling the trigger.