In  sre_compile.py line 473 stands: 
 
    # XXX: <fl> get rid of this limitation! 
    assert p.pattern.groups <= 100,\ 
           "sorry, but this version only supports 100 named groups" 
 
In sre.h line 53: 
/* FIXME: <fl> shouldn't be a constant, really... */ 
#define SRE_MARK_SIZE 200 
 
Small problem: the two numbers do not to match. 
 
Big problem: if this limitation cannot be eliminated (as 
suggested by the comments), I suggest setting SRE_MARK_SIZE 
of at least 1000.