Finding minima of a convex list using binary seach in python

def bin_search(lis,first,end):
	mid = (first+end)//2
	if (end - first)<2:
		if lis[end]>lis[first]:
			print(lis[first])
		else:
			print(lis[end])
	elif(lis[mid]>lis[mid+1]):
		bin_search(lis,mid,end)
	else:
		bin_search(lis,first,mid)


def minima(a):
	b = bin_search(a,0,len(a)-1)
	return(b)