Jul 12, 2011 · I want to define a two-dimensional array without an initialized length like this: Matrix = [][] But this gives an error: IndexError: list index out of range

@codemuncher The reason that [[0] * col] * row doesn't do what you want is because when you initialize a 2d list that way, Python will not create distinct copies of each row. Instead it will init …

Jun 8, 2014 · It's a good idea to get in the habit of saying list when you mean list and reserving array for numpy ndarray s. There's actually a built-in array module with its own array type, so …

I want to create an empty array and append items to it, one at a time. xs = [] for item in data: xs.append(item) Can I use this list-style notation with NumPy arrays?

105 If you wish to combine two 10 element one-dimensional arrays into a two-dimensional array, np.vstack((tp, fp)).T will do it. np.vstack((tp, fp)) will return an array of shape (2, 10), and the T …

Aug 14, 2012 · very new to python so attempting to wrap my head around multi dimensional arrays. I read the existing posts and most of them deal with multi dimensional arrays given …

Feb 15, 2016 · 4 This question already has answers here: How to initialize a two-dimensional array (list of lists, if not using NumPy) in Python? (31 answers) How can I collect the results of …

I need to make a multidimensional array of zeros. For two (D=2) or three (D=3) dimensions, this is easy and I'd use: a = numpy.zeros(shape=(n,n)) or a = numpy.zeros(shape=(n,n,n)) How for I for

I want to create a 2D array of values from the third row based on their x,y coordinates in the file. I read in each column as an individual array, and I created grids of x values and y values using …

There is no array type in python, but to emulate it we can use lists. I want to have 2d array-like structure filled in with zeros. My question is: what is the difference, if any, in this two expres...