Reverse and invert all integer values in a given list. 
Python:
    reverse_invert([1,12,'a',3.4,87,99.9,-42,50,5.6]) = [-1,-21,-78,24,-5]
Ignore all other types than integer.
def reverse_invert(lst):
    return [(-1)**(v>0)*int(str(abs(v))[::-1]) for v in lst if isinstance(v,int)]
def reverse_invert(lst):
    return [(-1)**(v>0)*int(str(abs(v))[::-1]) for v in lst if isinstance(v,int)]