On 10-5-2017 17:12, Mahmood Naderan wrote: > So, I think numpy is unable to manage the memory.
That assumption is very likely to be incorrect. >> np.array([[i.value for i in j] for j in p.rows]) I think the problem is in the way you feed your excel data into the numpy array constructor. The code above builds many redundant python lists from the data you already have in memory, before even calling the numpy array function. I strongly suggest finding a proven piece of code to read large excel files like the example from Peter Otten's reply. Irmen -- https://mail.python.org/mailman/listinfo/python-list
