def _diff_env(a, b):
 seta = set([(k, a[k]) for k in a])
 setb = set([(k, b[k]) for k in b])
 return (dict((seta - setb)), dict((setb - seta)))

def _diff_env ( a , b ) : seta = set ( [ ( k , a [ k ] ) for k in a ] ) setb = set ( [ ( k , b [ k ] ) for k in b ] ) return ( dict ( ( seta - setb ) ) , dict ( ( setb - seta ) ) )
return difference of two environments dict .