Finding positive peaks of a function

It is required to programmatically find the number and location of positive peaks on the graph.
It is known that the number of peaks is odd. Usually 3, 5 or 7. In this case, 3. It is also known that each positive peak is followed by a negative one.
What is the best way to solve this problem in Python? Preferably without coefficient tuning
Addition: The data always starts with a positive peak and ends with a negative one.
The data is a vertical projection of an image processed by the function np.gradient(projection)/projection. That is, the ratio of the second derivative of the function to its height.