python array/cell/indexing - Printable Version +- Python Forum (https://python-forum.io) +-- Forum: Python Coding (https://python-forum.io/forum-7.html) +--- Forum: Data Science (https://python-forum.io/forum-44.html) +--- Thread: python array/cell/indexing (/thread-8174.html) |
python array/cell/indexing - python - Feb-08-2018 Hello fellow programmers! I recently started to learn python (previousely matlab) and I was hopeing some of you might be able help me with a specific problem. I am trying to create a list in which each element contains a matrix. I then want to access each entry seperately. Easier with example I think. All values are integer. So I want a list shape = (n,). -> Each element of that list I want to be a matrix (shape = (n,n)). -> Now I want to access the first element of that list (so list(0,0) = first matrix). -> Additionally I want to access each value of the selected matrix seperately. So bsically my 0,0 listelement and my 0,0 matrixelement --- this should be an integer value Does python approve or not? RE: python array/cell/indexing - DeaD_EyE - Feb-08-2018 With numpy: import numpy as np shape = (2,5) arr1 = np.zeros(shape) print(arr1)With stock Python: shape = (2,5) arr2 = [] fill_value = 0 for a in range(shape[0]): row = [] for b in range(shape[1]): row.append(fill_value) arr2.append(row) print(arr2)Accessing multi dimensional lists with stock Python: arr2[0][1] arr2[0][0:2]Same with numpy: arr1[0,1] arr1[0,0:2]More complex stuff with numpy: arr1[:,::2]Returns all rows, from each row the even fields are selected. |