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])
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), ...
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()
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Python Two Dimensional Numpy Arrays - YouTube
DataCamp
campus.datacamp.com › courses › intro-to-python-for-data-science › chapter-4-numpy
2D NumPy Arrays | Python
The arrays np_height and np_weight are one-dimensional arrays, but it's perfectly possible to create 2 dimensional, three dimensional, heck even seven dimensional arrays! Let's stick to 2 in this video though. You can create a 2D numpy array from a regular Python list of 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.
Sentry
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Define a two-dimensional array in Python | Sentry
The following code will create a 3-by-3 2D array with all values set to zero: import numpy matrix = numpy.zeros((3,3)) # array([[0., 0., 0.], # [0., 0., 0.], # [0., 0., 0.]])
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.
Python Guides
pythonguides.com › python-numpy-2d-array
Create A 2D NumPy Array In Python (5 Simple Methods)
May 16, 2025 - In this article, I’ll show you five easy methods to create 2D NumPy arrays (also known as matrices) based on my decade of experience working with Python.
OpenGenus
iq.opengenus.org › 2d-array-in-numpy
2D Arrays in NumPy (Python)
October 28, 2022 - For working with numpy we need to first import it into python code base. ... To get a specific element from an array use arr[r,c] here r specifies row number and c column number.
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 ...
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 ...
W3Schools
w3schools.com › python › numpy › numpy_creating_arrays.asp
NumPy Creating Arrays
An array that has 1-D arrays as its elements is called a 2-D array. These are often used to represent matrix or 2nd order tensors. NumPy has a whole sub module dedicated towards matrix operations called numpy.mat
Programiz
programiz.com › python-programming › numpy › ndarray-creation
NumPy N-D Array Creation (With Examples)
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)
Indian AI Production
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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.
GeeksforGeeks
geeksforgeeks.org › python-using-2d-arrays-lists-the-right-way
Python | Using 2D arrays/lists the right way - GeeksforGeeks
Given a 3D list, the task is to convert it into a 2D list. These type of problems are encountered while working on projects or w ... Python's NumPy package makes slicing multi-dimensional arrays a valuable tool for data manipulation and analysis.
Published: June 20, 2024
W3Schools
w3schools.com › python › numpy › numpy_array_iterating.asp
NumPy Array Iterating
import numpy as np arr = np.array([1, 2, 3]) for x in np.nditer(arr, flags=['buffered'], op_dtypes=['S']): print(x) Try it Yourself » · We can use filtering and followed by iteration. Iterate through every scalar element of the 2D array skipping 1 element:
Fabienmaussion
fabienmaussion.info › intro_to_programming › week_09 › 01-multidim-numpy.html
Multi-dimensional numpy arrays — Introduction to Programming
For the final two weeks of the semester, you will learn to manipulate multi-dimensional arrays (ndarrays) which are very common in meteorology, climatology, and geosciences in general. import numpy as np import matplotlib.pyplot as plt
NumPy
numpy.org › devdocs › user › basics.creation.html
Array creation — NumPy v2.6.dev0 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 ...
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 ...
Data Science Dojo
discuss.datasciencedojo.com › python
How to create a two-dimensional array using NumPy? - Python - Data Science Dojo Discussions
May 15, 2023 - I have comprehended multiple methods that assist me in defining a one-dimensional array using NumPy. Now, I aspire to master methods that help in developing a two-dimensional array. For this purpose, I have found one met…