This works:
a = [[1, 2, 3], [4, 5, 6]]
nd_a = np.array(a)
So this should work too:
nd_a = np.array([[x for x in y] for y in a])
Top answer 1 of 3
21
This works:
a = [[1, 2, 3], [4, 5, 6]]
nd_a = np.array(a)
So this should work too:
nd_a = np.array([[x for x in y] for y in a])
2 of 3
11
To create a new array, it seems numpy.zeros is the way to go
import numpy as np
a = np.zeros(shape=(x, y))
You can also set a datatype to allocate it sensibly
>>> np.zeros(shape=(5,2), dtype=np.uint8)
array([[0, 0],
[0, 0],
[0, 0],
[0, 0],
[0, 0]], dtype=uint8)
>>> np.zeros(shape=(5,2), dtype="datetime64[ns]")
array([['1970-01-01T00:00:00.000000000', '1970-01-01T00:00:00.000000000'],
['1970-01-01T00:00:00.000000000', '1970-01-01T00:00:00.000000000'],
['1970-01-01T00:00:00.000000000', '1970-01-01T00:00:00.000000000'],
['1970-01-01T00:00:00.000000000', '1970-01-01T00:00:00.000000000'],
['1970-01-01T00:00:00.000000000', '1970-01-01T00:00:00.000000000']],
dtype='datetime64[ns]')
See also
- How do I create an empty array/matrix in NumPy?
- np.full(size, 0) vs. np.zeros(size) vs. np.empty()
NumPy
numpy.org › doc › stable › reference › arrays.ndarray.html
The N-dimensional array (ndarray) — NumPy v2.5 Manual
The type of items in the array is specified by a separate data-type object (dtype), one of which is associated with each ndarray. As with other container objects in Python, the contents of an ndarray can be accessed and modified by indexing or slicing the array (using, for example, N integers), and via the methods and attributes of the ndarray.
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Sentry
sentry.io › sentry answers › python › define a two-dimensional array in python
Python Define a Two-Dimensional Array or Matrix | Sentry
September 23, 2026 - Create a 2D array in Python using numpy.zeros for matrix operations, or a nested list comprehension if you want to avoid the numpy dependency
W3Schools
w3schools.com › python › numpy › numpy_creating_arrays.asp
NumPy Creating Arrays
Like in above code it shows that arr is numpy.ndarray type. To create an ndarray, we can pass a list, tuple or any array-like object into the array() method, and it will be converted into an ndarray: ... A dimension in arrays is one level of array depth (nested arrays). nested array: are arrays that have arrays as their elements. 0-D arrays, or Scalars, are the elements in an array. Each value in an array is a 0-D array.
Python Guides
pythonguides.com › python-numpy-2d-array
Create A 2D NumPy Array In Python (5 Simple Methods)
May 9, 2025 - A 2D array in Python is a table of values arranged in rows and columns. Python has no built-in 2D array type, so you use either a nested list (a list of rows, like [[1, 2], [3, 4]]) or a NumPy 2D array created with np.array(), np.zeros() and ...
Drbeane
drbeane.github.io › python_dsci › pages › array_2d.html
2-Dimensional Arrays — Python for Data Science
The arrays we have worked with up to this point have all been one-dimensional arrays which consist of a sequence of numbers in a linear order. Numpy provides us with tools for creating and working with higher dimensional arrays. In this lesson, we will work exclusively with 2D arrays, which consist of several values arranged into ordered rows and columns.
NumPy
numpy.org › doc › stable › user › basics.creation.html
Array creation — NumPy v2.5 Manual
NumPy arrays can be defined using Python sequences such as lists and tuples. Lists and tuples are defined using [...] and (...), respectively. Lists and tuples can define ndarray creation: a list of numbers will create a 1D array, a list of lists will create a 2D array, further nested lists ...
Medium
medium.com › @bouimouass.o › what-does-a-numpy-2d-array-look-like-in-python-38752ccde895
What does a numpy 2D array look like in python? | by Omar | Medium
July 23, 2023 - As you can see, the array has 3 rows and 4 columns. The first row contains the numbers 1, 2, 3, and 4. The second row contains the numbers 5, 6, 7, and 8. The third row contains the numbers 9, 10, 11, and 12. You can also create a 2D NumPy array using the arange() function.
w3resource
w3resource.com › python-exercises › numpy › python-numpy-exercise-37.php
Python NumPy: Create a 2-dimensional array of size 2 x 3 - w3resource
August 29, 2025 - Write a NumPy program to create a 2-dimensional array of size 2 x 3 (composed of 4-byte integer elements), also print the shape, type and data type of the array. ... # Importing the NumPy library with an alias 'np' import numpy as np # Creating ...
Programiz
programiz.com › python-programming › numpy › ndarray-creation
NumPy N-D Array Creation (With Examples)
May 22, 2023 - We saw how to create N-d NumPy arrays from Python lists. Now we'll see how we can create them from scratch. To create multidimensional arrays from scratch we use functions such as ... The np.zeros() function allows us to create N-D arrays filled with all zeros. For example, ... # create 2D array with 2 rows and 3 columns filled with zeros array1 = np.zeros((2, 3)) print("2-D Array: ") print(array1)
NumPy
numpy.org › devdocs › user › absolute_beginners.html
NumPy: the absolute basics for beginners — NumPy v2.6.dev0 Manual
Using np.newaxis will increase the dimensions of your array by one dimension when used once. This means that a 1D array will become a 2D array, a 2D array will become a 3D array, and so on.
AskPython
askpython.com › python › array › multidimensional-arrays
Multidimensional Arrays in Python: A Complete Guide - AskPython
February 27, 2023 - #To install the Numpy package pip install numpy #To import the Numpy package import numpy as np · An array of arrays is a simple definition that applies to the two-dimensional array.
freeCodeCamp
freecodecamp.org › news › multi-dimensional-arrays-in-python
Multi-Dimensional Arrays in Python – Matrices Explained with Examples
December 11, 2025 - In Python, you can create multi-dimensional arrays using various libraries, such as NumPy, Pandas, and TensorFlow.
MLJAR
mljar.com › answers › define-two-dimensional-array-python
Define two-dimensional array in Python
array[2][2] = 5 # valid array[7][2] = 3 # error · This way is much easier. You can use zeros function from numpy to create 2D array with all values set to zero: import numpy array = numpy.zeros((4,4)) REMEMBER Even though the second version is easier, the first one is better for this operation unless we need any matrix operations.
GeeksforGeeks
geeksforgeeks.org › python › manipulating-multidimensional-arrays-in-python-numpy
Manipulating Multidimensional Arrays in Python NumPy - GeeksforGeeks
February 19, 2026 - Each nested structure represents a new dimension in the array. 1. 2D Array from List of Lists: NumPy's np.array() function can create a 2D array from a list of lists, where each sub-list represents a row in the array.
Sdsu
gawron.sdsu.edu › python_for_ss › course_core › book_draft › data › numpy.html
6.2. More on two-dimensional arrays — python_for_ss 0.1.1 documentation
In this case, though, using the array operation is about an order of magnitude less efficient than the natural Pythonic idiom. ... More on array operations and efficiency below. It’s a tricky subject. Boolean operations work more or less as expected on 2D arrays: import numpy as np y = np.arange(35).reshape(5,7) y>3
Indian AI Production
indianaiproduction.com › home › blog › python numpy array – create numpy ndarray (multidimensional array)
Python NumPy array - Create NumPy ndarray (multidimensional array)
June 12, 2019 - In machine learning and data science NumPy 1D array known as vector. Specially use to store and perform an operation on target values. To create NumPy 2D array use array() function and give one argument of items of lists of the list to it.
NumPy
numpy.org › doc › 2.1 › reference › arrays.ndarray.html
The N-dimensional array (ndarray) — NumPy v2.1 Manual
The type of items in the array is specified by a separate data-type object (dtype), one of which is associated with each ndarray. As with other container objects in Python, the contents of an ndarray can be accessed and modified by indexing or slicing the array (using, for example, N integers), and via the methods and attributes of the ndarray.
Scaler
scaler.com › home › topics › matplotlib › how to visualize a 2d array?
How to Visualize a 2D Array? | Scaler Topics
June 5, 2024 - Matplotlib and Numpy provide the modules and functions to visualize a 2D array in Python. To visualize an array or list in matplotlib, we have to generate the data, which the NumPy library can do, and then plot the data using matplotlib. There are many functions by which we can add data to ...
NumPy
numpy.org › doc › 2.2 › reference › arrays.ndarray.html
The N-dimensional array (ndarray) — NumPy v2.2 Manual
Arrays can be indexed using an extended Python slicing syntax, array[selection]. Similar syntax is also used for accessing fields in a structured data type.