What is the difference between ndarray and array in Numpy? And where can I find the implementations in the numpy source code?
ndarray和Numpy中的数组有什么区别?在numpy源代码中我可以在哪里找到实现?
3 个解决方案
#1
114
Well, numpy.array is just a convenience function to create an ndarray, it is not a class itself.
嗯,numpy。数组只是创建ndarray的一个方便函数，它本身不是类。
You can also create an array using numpy.ndarray, but it is not the recommended way. From the docstring of numpy.ndarray:
您还可以使用numpy创建一个数组。恩达雷，但这不是推荐的方法。来自numpy.ndarray的docstring:
Arrays should be constructed using
array,zerosorempty... The parameters given here refer to a low-level method (ndarray(...)) for instantiating an array.数组应该使用数组、0或空来构造……这里给出的参数指的是用于实例化数组的低级方法(ndarray(…))。
Most of the meat of the implementation is in C code, here in multiarray, but you can start looking at the ndarray interfaces here:
实现的大部分内容都在C代码中，这里是multiarray，但是你可以在这里查看ndarray接口:
https://github.com/numpy/numpy/blob/master/numpy/core/numeric.py
https://github.com/numpy/numpy/blob/master/numpy/core/numeric.py
#2
30
numpy.array is a function that returns a numpy.ndarray. There is no object type numpy.array.
numpy。数组是返回numpi .ndarray的函数。没有对象类型numpi .array。
#3
9
Just a few lines of example code to show the difference between numpy.array and numpy.ndarray
只需要几行代码来显示numpy的区别。数组和numpy.ndarray
Warm up step: Construct a list
热身步骤:构建一个列表。
a = [1,2,3]
Check the type
检查类型
print(type(a))
You will get
你会得到
<class 'list'>
Construct an array (from a list) using np.array
使用np.array构造一个数组(从列表中)。
a = np.array(a)
Or, you can skip the warm up step, directly have
或者，你可以跳过热身步骤，直接有
a = np.array([1,2,3])
Check the type
检查类型
print(type(a))
You will get
你会得到
<class 'numpy.ndarray'>
which tells you the type of the numpy array is numpy.ndarray
这告诉你numpy数组的类型是numpy.ndarray ?
You can also check the type by
您也可以检查类型by
isinstance(a, (np.ndarray))
and you will get
你会得到
True
The following two line will give you error message
下面两行将给出错误消息
np.ndarray(a) # should be np.array(a)
isinstance(a, (np.array)) # should be isinstance(a, (np.ndarray))
#1
114
Well, numpy.array is just a convenience function to create an ndarray, it is not a class itself.
嗯,numpy。数组只是创建ndarray的一个方便函数，它本身不是类。
You can also create an array using numpy.ndarray, but it is not the recommended way. From the docstring of numpy.ndarray:
您还可以使用numpy创建一个数组。恩达雷，但这不是推荐的方法。来自numpy.ndarray的docstring:
Arrays should be constructed using
array,zerosorempty... The parameters given here refer to a low-level method (ndarray(...)) for instantiating an array.数组应该使用数组、0或空来构造……这里给出的参数指的是用于实例化数组的低级方法(ndarray(…))。
Most of the meat of the implementation is in C code, here in multiarray, but you can start looking at the ndarray interfaces here:
实现的大部分内容都在C代码中，这里是multiarray，但是你可以在这里查看ndarray接口:
https://github.com/numpy/numpy/blob/master/numpy/core/numeric.py
https://github.com/numpy/numpy/blob/master/numpy/core/numeric.py
#2
30
numpy.array is a function that returns a numpy.ndarray. There is no object type numpy.array.
numpy。数组是返回numpi .ndarray的函数。没有对象类型numpi .array。
#3
9
Just a few lines of example code to show the difference between numpy.array and numpy.ndarray
只需要几行代码来显示numpy的区别。数组和numpy.ndarray
Warm up step: Construct a list
热身步骤:构建一个列表。
a = [1,2,3]
Check the type
检查类型
print(type(a))
You will get
你会得到
<class 'list'>
Construct an array (from a list) using np.array
使用np.array构造一个数组(从列表中)。
a = np.array(a)
Or, you can skip the warm up step, directly have
或者，你可以跳过热身步骤，直接有
a = np.array([1,2,3])
Check the type
检查类型
print(type(a))
You will get
你会得到
<class 'numpy.ndarray'>
which tells you the type of the numpy array is numpy.ndarray
这告诉你numpy数组的类型是numpy.ndarray ?
You can also check the type by
您也可以检查类型by
isinstance(a, (np.ndarray))
and you will get
你会得到
True
The following two line will give you error message
下面两行将给出错误消息
np.ndarray(a) # should be np.array(a)
isinstance(a, (np.array)) # should be isinstance(a, (np.ndarray))