Numerous RuntimeWarning for internal procedures

[Yachter]

Hello!

1. In most of my cases by calling wallstreet_obj.delta() causes this warning:

C:\Program Files\Python38\lib\site-packages\wallstreet\blackandscholes.py:58: RuntimeWarning: divide by zero encountered in double_scalars
d1 = (log(S/K) + (r - q + (sigma**2)/2)T)/(sigmasqrt(T))

2. also there is another annoying warning for this line:

wallstreet_obj.set_strike(float(str))

d:\Program Files\Python38\lib\site-packages\scipy\optimize\minpack.py:162: RuntimeWarning: The iteration is not making good progress, as measured by the
improvement from the last ten iterations.

Please check it out.

Regards.