使用NumPy对数组进行拆分是一种高效且灵活的数据处理方式。NumPy提供了多种函数，如numpy.split(), numpy.hsplit(), 和 numpy.vsplit()，使得数组可以根据不同的需求进行拆分。这些函数能够精确控制拆分的数量和位置，满足不同的数据处理和分析需求。例如，numpy.split()可以按照指定的份数或索引位置将数组分割成多个子数组；而numpy.hsplit()和numpy.vsplit()则分别用于沿数组的水平和垂直方向进行拆分。通过这些拆分操作，用户可以轻松地将复杂的数据集划分为更小的、更易于管理的部分，从而简化数据处理流程，提高数据处理效率。
1.np.vsplit()：垂直拆分，需要等分
# 导包import numpy as np# 创建一个6行4列的二维数组n = np.random.randint(0,100,size=(6,4))n# 执行结果array([[11, 47, 82, 13],[17, 66, 24, 53],[84, 10, 72, 20],[83, 33, 7, 23],[19, 67, 13, 19],[70, 50, 39, 81]])# np.vsplit：垂直拆分，需要等分np.vsplit(n,3) # 平均拆成3份# 执行结果[array([[11, 47, 82, 13],[17, 66, 24, 53]]),array([[84, 10, 72, 20],[83, 33, 7, 23]]),array([[19, 67, 13, 19],[70, 50, 39, 81]])]# 可以按照指定的位置拆分：(0-1)，(1-2)，(2-4)，(4-最后）np.vsplit(n,(1,2,4))# 执行结果[array([[11, 47, 82, 13]]),array([[17, 66, 24, 53]]),array([[84, 10, 72, 20],[83, 33, 7, 23]]),array([[19, 67, 13, 19],[70, 50, 39, 81]])]
2.np.hsplit()：水平方向拆分
# 水平方向拆分np.hsplit(n,2)# 执行结果[array([[11, 47],[17, 66],[84, 10],[83, 33],[19, 67],[70, 50]]),array([[82, 13],[24, 53],[72, 20],[ 7, 23],[13, 19],[39, 81]])]# 可以按照指定的位置拆分：(0-1)，(1-2)，(2-最后）np.hsplit(n,(1,2))# 执行结果[array([[11, 47],[17, 66],[84, 10],[83, 33],[19, 67],[70, 50]]),array([[82, 13],[24, 53],[72, 20],[ 7, 23],[13, 19],[39, 81]])]# 可以按照指定的位置拆分：(0-1)，(1-2)，(2-最后）np.hsplit(n,(1,2))# 执行结果[array([[11],[17],[84],[83],[19],[70]]),array([[47],[66],[10],[33],[67],[50]]),array([[82, 13],[24, 53],[72, 20],[ 7, 23],[13, 19],[39, 81]])]
3.np.split()：可以做水平或垂直拆分
# split：可以做水平或垂直拆分，axis=0 行，axis=1 列# 默认按行拆分np.split(n,2)# 执行结果[array([[11, 47, 82, 13],[17, 66, 24, 53],[84, 10, 72, 20]]),array([[83, 33, 7, 23],[19, 67, 13, 19],[70, 50, 39, 81]])]# 按行拆分np.split(n,2,axis=0)# 执行结果[array([[11, 47, 82, 13],[17, 66, 24, 53],[84, 10, 72, 20]]),array([[83, 33, 7, 23],[19, 67, 13, 19],[70, 50, 39, 81]])]# 按列拆分np.split(n,2,axis=1)# 执行结果[array([[11, 47],[17, 66],[84, 10],[83, 33],[19, 67],[70, 50]]),array([[82, 13],[24, 53],[72, 20],[ 7, 23],[13, 19],[39, 81]])]
4.案例：把图片拆分
# 数据分析三剑客import numpy as npimport pandas as pdimport matplotlib.pyplot as plt# python.png# 图片：其实时数字组成的，三维数组# RGB：红Red，绿Green，蓝Blue# RGB范围：0-255# plt.imread：读取图片的数据pyimg = plt.imread("python.png")pyimgprint(pyimg.shape)# 执行结果(539, 1080, 4)# 切片img = pyimg[:-1]img.shape# 执行结果(538, 1080, 4)plt.imshow(img)# 垂直拆分img1 = np.split(img,2)img1# 执行结果[array([[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]],[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]],[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]],...,[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]],[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]],[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]]], dtype=float32),array([[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]],[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]],[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]],...,[[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],...,[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ]],[[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],...,[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ]],[[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],...,[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ]]], dtype=float32)]# 图片上半部分plt.imshow(img1[0])# 图片下半部分plt.imshow(img1[1])# 水平拆分成5等份img2 = np.split(img,5,axis=1)img2# 执行结果[array([[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ]],[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ]],[[0.09019608, 0.15294118, 0.24313726, 1. ],[0.05882353, 0.12156863, 0.21176471, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ],...,[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ]],...,[[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],...,[0.11372549, 0.29803923, 0.64705884, 1. ],[0.11764706, 0.29411766, 0.6509804 , 1. ],[0.11764706, 0.29411766, 0.6509804 , 1. ]],[[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],...,[0.11372549, 0.29803923, 0.64705884, 1. ],[0.11764706, 0.29411766, 0.6509804 , 1. ],[0.11764706, 0.29411766, 0.6509804 , 1. ]],[[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],...,[0.11372549, 0.29803923, 0.64705884, 1. ],[0.11764706, 0.29411766, 0.6509804 , 1. ],[0.11764706, 0.29411766, 0.6509804 , 1. ]]], dtype=float32),array([[[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],...,[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ]],[[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],...,[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ]],[[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],...,[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ]],...,[[0.11764706, 0.29411766, 0.6509804 , 1. ],[0.11764706, 0.29411766, 0.6509804 , 1. ],[0.12156863, 0.29803923, 0.654902 , 1. ],...,[0.5294118 , 0.72156864, 0.9490196 , 1. ],[0.53333336, 0.7294118 , 0.95686275, 1. ],[0.5254902 , 0.7254902 , 0.9607843 , 1. ]],[[0.11764706, 0.29411766, 0.6509804 , 1. ],[0.11764706, 0.29411766, 0.6509804 , 1. ],[0.12156863, 0.29803923, 0.654902 , 1. ],...,[0.53333336, 0.7254902 , 0.9529412 , 1. ],[0.5372549 , 0.73333335, 0.9607843 , 1. ],[0.5254902 , 0.7254902 , 0.9607843 , 1. ]],[[0.11764706, 0.29411766, 0.6509804 , 1. ],[0.12156863, 0.29803923, 0.654902 , 1. ],[0.1254902 , 0.3019608 , 0.65882355, 1. ],...,[0.5372549 , 0.7294118 , 0.95686275, 1. ],[0.54509807, 0.7372549 , 0.96862745, 1. ],[0.53333336, 0.73333335, 0.96862745, 1. ]]], dtype=float32),array([[[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ],...,[0.10196079, 0.21176471, 0.39607844, 1. ],[0.10196079, 0.21176471, 0.4 , 1. ],[0.10196079, 0.21176471, 0.4 , 1. ]],[[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ],...,[0.10196079, 0.21176471, 0.39607844, 1. ],[0.10196079, 0.21176471, 0.4 , 1. ],[0.10196079, 0.21176471, 0.4 , 1. ]],[[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ],[0.11372549, 0.21960784, 0.40392157, 1. ],...,[0.10196079, 0.21176471, 0.39607844, 1. ],[0.10196079, 0.21176471, 0.4 , 1. ],[0.10196079, 0.21176471, 0.4 , 1. ]],...,[[0.5176471 , 0.7176471 , 0.9647059 , 1. ],[0.5137255 , 0.7254902 , 0.972549 , 1. ],[0.52156866, 0.73333335, 0.9843137 , 1. ],...,[0.05882353, 0.19607843, 0.41568628, 1. ],[0.06666667, 0.19215687, 0.41568628, 1. ],[0.07058824, 0.19607843, 0.41960785, 1. ]],[[0.52156866, 0.72156864, 0.96862745, 1. ],[0.5176471 , 0.7294118 , 0.9764706 , 1. ],[0.5254902 , 0.7372549 , 0.9882353 , 1. ],...,[0.05882353, 0.19607843, 0.42352942, 1. ],[0.06666667, 0.19215687, 0.42352942, 1. ],[0.07058824, 0.19607843, 0.42745098, 1. ]],[[0.5254902 , 0.7254902 , 0.972549 , 1. ],[0.52156866, 0.73333335, 0.98039216, 1. ],[0.5294118 , 0.7411765 , 0.99215686, 1. ],...,[0.0627451 , 0.19607843, 0.42352942, 1. ],[0.07058824, 0.19607843, 0.42745098, 1. ],[0.07058824, 0.19607843, 0.42745098, 1. ]]], dtype=float32),array([[[0.10196079, 0.21176471, 0.4 , 1. ],[0.10196079, 0.21176471, 0.4 , 1. ],[0.10196079, 0.21176471, 0.4 , 1. ],...,[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.09803922, 0.17254902, 0.2901961 , 1. ]],[[0.10196079, 0.21176471, 0.4 , 1. ],[0.10196079, 0.21176471, 0.4 , 1. ],[0.10196079, 0.21176471, 0.4 , 1. ],...,[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.09803922, 0.17254902, 0.2901961 , 1. ]],[[0.10196079, 0.21176471, 0.4 , 1. ],[0.10196079, 0.21176471, 0.4 , 1. ],[0.10196079, 0.21176471, 0.4 , 1. ],...,[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.10196079, 0.1764706 , 0.29411766, 1. ],[0.09803922, 0.17254902, 0.2901961 , 1. ]],...,[[0.07058824, 0.19607843, 0.42745098, 1. ],[0.07058824, 0.1882353 , 0.42352942, 1. ],[0.06666667, 0.18431373, 0.41960785, 1. ],...,[0.23921569, 0.5176471 , 0.8627451 , 1. ],[0.23921569, 0.5176471 , 0.8627451 , 1. ],[0.23921569, 0.5176471 , 0.8627451 , 1. ]],[[0.07058824, 0.19607843, 0.42745098, 1. ],[0.07058824, 0.1882353 , 0.42352942, 1. ],[0.06666667, 0.18431373, 0.41960785, 1. ],...,[0.1882353 , 0.4862745 , 0.8627451 , 1. ],[0.1882353 , 0.4862745 , 0.8627451 , 1. ],[0.1882353 , 0.4862745 , 0.8627451 , 1. ]],[[0.07058824, 0.19607843, 0.42745098, 1. ],[0.07058824, 0.1882353 , 0.42352942, 1. ],[0.06666667, 0.18431373, 0.41960785, 1. ],...,[0.16470589, 0.47843137, 0.8666667 , 1. ],[0.16470589, 0.47843137, 0.8666667 , 1. ],[0.16470589, 0.47843137, 0.8666667 , 1. ]]], dtype=float32),array([[[0.09411765, 0.16862746, 0.28627452, 1. ],[0.10196079, 0.1764706 , 0.2901961 , 1. ],[0.10196079, 0.18039216, 0.28627452, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]],[[0.09411765, 0.16862746, 0.28627452, 1. ],[0.10196079, 0.1764706 , 0.2901961 , 1. ],[0.10196079, 0.18039216, 0.28627452, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]],[[0.09411765, 0.16862746, 0.28627452, 1. ],[0.10196079, 0.1764706 , 0.2901961 , 1. ],[0.10196079, 0.18039216, 0.28627452, 1. ],...,[0.05490196, 0.11764706, 0.20784314, 1. ],[0.05098039, 0.11372549, 0.20392157, 1. ],[0.08235294, 0.14509805, 0.23529412, 1. ]],...,[[0.23921569, 0.5176471 , 0.8627451 , 1. ],[0.23921569, 0.5176471 , 0.8627451 , 1. ],[0.23921569, 0.5176471 , 0.8627451 , 1. ],...,[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ]],[[0.1882353 , 0.4862745 , 0.8627451 , 1. ],[0.1882353 , 0.4862745 , 0.8627451 , 1. ],[0.1882353 , 0.4862745 , 0.8627451 , 1. ],...,[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ]],[[0.16470589, 0.47843137, 0.8666667 , 1. ],[0.16470589, 0.47843137, 0.8666667 , 1. ],[0.16470589, 0.47843137, 0.8666667 , 1. ],...,[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ],[0.0627451 , 0.25882354, 0.5294118 , 1. ]]], dtype=float32)]# 显示第三部分图片plt.imshow(img2[2])
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