numpy的concatenate函数

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concatenate((a1, a2, …), axis=0)

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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
    --------

Parameters参数

传入的参数必须是一个多个数组的元组或者列表

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。
拼接的数组要满足在拼接方向axis轴上数组间的形状一致即可

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