npy-append-array 0.9.4

Allows to create Numpy `.npy` files that are larger than the main memory

NpyAppendArray

Allows to create Numpy .npy files that are larger than the main memory of the machine by appending on the zero axis. The file can then be read with mmap_mode="r".

from npy_append_array import NpyAppendArray
import numpy as np

arr1 = np.array([[1,2],[3,4]])
arr2 = np.array([[1,2],[3,4],[5,6]])

filename='out.npy'

# line may be removed, still works correctly if filename does not exist
np.save(filename, arr1)

npaa = NpyAppendArray(filename)
npaa.append(arr2)
npaa.append(arr2)
npaa.append(arr2)

data = np.load(filename, mmap_mode="r")

print(data)