L = [1,2,3,4,1,2,3,4,0,2]
def dicho(x,L):
g = 0
d = len(L)-1
while g <= d:
m = (g+d)//2
if L[m] == x:
return m
elif L[m] < x:
g = m+1
else:
d = m-1
return None