Ｐython讲堂 数组拼接---np.concatenate官方文档详解与实例

https://blog.csdn.net/brucewong0516/article/details/79158758

Parameters参数

numpy库中一般

axis=0 => 表示列  纵向
axis=1 => 表示行  横向

np.concatenate()

传入的参数必须是一个多个数组的元组或者列表

a = np.array([ [1,2], [3,4]])
b = np.array([[5,6]])
a,b 是数组    
(a, b)是元组

另外需要指定拼接的方向，默认是 axis = 0，
也就是说对0轴的数组对象进行纵向的拼接（纵向的拼接沿着axis= 1方向）；
注：一般axis = 0，就是对该轴向的数组进行操作，
操作方向是另外一个轴，即axis=1, 横向拼接。

In [23]: a = np.array([[1, 2], [3, 4]])

In [24]: b = np.array([[5, 6]])

In [25]: np.concatenate((a, b), axis=0)
Out[25]:
array([[1, 2],
       [3, 4],
       [5, 6]])

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官方示例

concatenate(...)
    concatenate((a1, a2, ...), axis=0)

    Join a sequence of arrays along an existing axis.

    Parameters
    ----------
    a1, a2, ... : sequence of array_like
        The arrays must have the same shape, except in the dimension
        corresponding to `axis` (the first, by default).
    axis : int, optional
        The axis along which the arrays will be joined.  Default is 0.

    Returns
    -------
    res : ndarray
        The concatenated array.

    See Also
    --------
    ma.concatenate : Concatenate function that preserves input masks.
    array_split : Split an array into multiple sub-arrays of equal or
                  near-equal size.
    split : Split array into a list of multiple sub-arrays of equal size.
    hsplit : Split array into multiple sub-arrays horizontally (column wise)
    vsplit : Split array into multiple sub-arrays vertically (row wise)
    dsplit : Split array into multiple sub-arrays along the 3rd axis (depth).
    stack : Stack a sequence of arrays along a new axis.
    hstack : Stack arrays in sequence horizontally (column wise)
    vstack : Stack arrays in sequence vertically (row wise)
    dstack : Stack arrays in sequence depth wise (along third dimension)