i want to pickle a large (1810392*255) numpy array. However when pickling i get an error: [...]error: 'i' format requires -2147483648 <= number <= 2147483647 Code: import numpy import pickle l=numpy.zeros((1810392,255)) f=open('file.pkl','wb') pickle.dump(l,f,2) Is there a size limit? Is there a workaround? If not necessary I do not want to use hdf5 or something not build into python. I also tried numpy.savez and numpy.savez_compressed. Code: import numpy l=numpy.zeros((1810392,255)) numpy.savez_compressed('file.npz',l) Saving works but when i try to load the data I get an error. Code: import numpy l=numpy.load('file.npz') l['arr_0'] I need to use numpy.savez instead of numpy.save because I want to store additional data. Continue reading...