[python] What is the difference between ndarray and array in numpy?

numpy.ndarray() is a class, while numpy.array() is a method / function to create ndarray.

In numpy docs if you want to create an array from ndarray class you can do it with 2 ways as quoted:

1- using array(), zeros() or empty() methods: Arrays should be constructed using array, zeros or empty (refer to the See Also section below). The parameters given here refer to a low-level method (ndarray(…)) for instantiating an array.

2- from ndarray class directly: There are two modes of creating an array using __new__: If buffer is None, then only shape, dtype, and order are used. If buffer is an object exposing the buffer interface, then all keywords are interpreted.

The example below gives a random array because we didn't assign buffer value:

np.ndarray(shape=(2,2), dtype=float, order='F', buffer=None)

array([[ -1.13698227e+002,   4.25087011e-303],
       [  2.88528414e-306,   3.27025015e-309]])         #random

another example is to assign array object to the buffer example:

>>> np.ndarray((2,), buffer=np.array([1,2,3]),
...            offset=np.int_().itemsize,
...            dtype=int) # offset = 1*itemsize, i.e. skip first element
array([2, 3])

from above example we notice that we can't assign a list to "buffer" and we had to use numpy.array() to return ndarray object for the buffer

Conclusion: use numpy.array() if you want to make a numpy.ndarray() object"

Examples related to python

programming a servo thru a barometer Is there a way to view two blocks of code from the same file simultaneously in Sublime Text? python variable NameError Why my regexp for hyphenated words doesn't work? Comparing a variable with a string python not working when redirecting from bash script is it possible to add colors to python output? Get Public URL for File - Google Cloud Storage - App Engine (Python) Real time face detection OpenCV, Python xlrd.biffh.XLRDError: Excel xlsx file; not supported Could not load dynamic library 'cudart64_101.dll' on tensorflow CPU-only installation

Examples related to arrays

PHP array value passes to next row Use NSInteger as array index How do I show a message in the foreach loop? Objects are not valid as a React child. If you meant to render a collection of children, use an array instead Iterating over arrays in Python 3 Best way to "push" into C# array Sort Array of object by object field in Angular 6 Checking for duplicate strings in JavaScript array what does numpy ndarray shape do? How to round a numpy array?

Examples related to numpy

Unable to allocate array with shape and data type How to fix 'Object arrays cannot be loaded when allow_pickle=False' for imdb.load_data() function? Numpy, multiply array with scalar TypeError: only integer scalar arrays can be converted to a scalar index with 1D numpy indices array Could not install packages due to a "Environment error :[error 13]: permission denied : 'usr/local/bin/f2py'" Pytorch tensor to numpy array Numpy Resize/Rescale Image what does numpy ndarray shape do? How to round a numpy array? numpy array TypeError: only integer scalar arrays can be converted to a scalar index

Examples related to multidimensional-array

what does numpy ndarray shape do? len() of a numpy array in python What is the purpose of meshgrid in Python / NumPy? Convert a numpy.ndarray to string(or bytes) and convert it back to numpy.ndarray Typescript - multidimensional array initialization How to get every first element in 2 dimensional list How does numpy.newaxis work and when to use it? How to count the occurrence of certain item in an ndarray? Iterate through 2 dimensional array Selecting specific rows and columns from NumPy array

Examples related to numpy-ndarray

what does numpy ndarray shape do? What is the purpose of meshgrid in Python / NumPy? Convert array of indices to 1-hot encoded numpy array How does numpy.newaxis work and when to use it? How to create a numpy array of all True or all False? What does -1 mean in numpy reshape? What is the difference between ndarray and array in numpy? Paritition array into N chunks with Numpy Concatenating two one-dimensional NumPy arrays How do I get indices of N maximum values in a NumPy array?