I need to find the max of all index items in a list, which is the efficient way, Does numpy have any function or efficient and best pythonic way, my list elements will length above 100, with each list with 20 elements.
eg:
[[1,2,3,4,5,6],[3,2,1,4,5,6],[4,3,2,1,5,6],[1,1,1,1,1,1]]
max_list = [4,3,3,4,5,6]
My list will length to around 100, with each inner list with 20 elements
Solution without numpy:
data = [[1,2,3,4,5,6],[3,2,1,4,5,6],[4,3,2,1,5,6],[1,1,1,1,1,1]]
list(map(max, *data))
The list is not needed in Python 2 (or even in Python 3, depending on what you're going to do with the result)
map can iterate on several lists at once.
data contains only one sublist or is empty.Also without numpy (but with help of comment authors)
inp = [[1,2,3,4,5,6],[3,2,1,4,5,6],[4,3,2,1,5,6],[1,1,1,1,1,1]]
out = [max(s) for s in zip(*inp)]
You can use the following:
a = np.array([[1,2,3,4,5,6],[3,2,1,4,5,6],[4,3,2,1,5,6],[1,1,1,1,1,1]])
a.max(0) #a.max(axis=0)
Which results in:
array([4, 3, 3, 4, 5, 6])
