where()
It’s used to search the array for a certain value.
arr = np.array(["APT", "Dynamite", "Crysalis Suspirii", "Glory"])
x = np.where(arr=="APT")
print(x) # (array([0], dtype=int64),)
We can set conditions for generating elements.
arr = np.array([1,3,57,43,6,2223,2])
x = np.where(arr%2==0)
print(x) # (array([4, 6], dtype=int64),)
searchsorted()
It performs a binary search on sorted arrays and returns the index of the element.
arr = np.array([1,3,57,43,6,2223,2])
x = np.searchsorted(arr,3)
print(x) # 1
By default, it returns the left-most index. To make it do the right-most index, we use side='right'.
arr = np.array([1,3,57,43,6,2223,2])
x = np.searchsorted(arr,3, side='right')
print(x) # 2
To search for multiple values, enclose them in brackets.
arr = np.array([1,3,57,43,6,2223,2])
x = np.searchsorted(arr, [3,6])
print(x) [1 2]