nn.py

def nn(a,b="¹²³⁴⅝"):
    if b=="¹²³⁴⅝":
        exec("nn.b=%s"%a,globals())
        return nn.b; del nn.b
    else:
        nn.b=b
        exec("%s=nn.b"%(a),globals())
        del nn.b

a="aa"
nn(a,123)
print(aa)
b="bb"
nn(b,a)
print(bb)
print(nn(a))
#print(globals())
nn(a, None)
print(nn(a))