43 lines
965 B
Python
43 lines
965 B
Python
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import numpy as np
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# reshape
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b1 = np.arange(15)
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b2 = b1.reshape((3,5))
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# b1 = [ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14]
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# b2 = [[ 0 1 2 3 4]
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# [ 5 6 7 8 9]
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# [10 11 12 13 14]]
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print(f"b1 = {b1} \n ")
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print(
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f"b1[0:5] = {b1[0:5]} \n "
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f"b1[-1] = {b1[-1]} \n "
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f"b1[0:-1] = {b1[0:-1]} \n "
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f"b1[:] = {b1[:]} \n "
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f"b1[5:-1] = {b1[5:7]} \n "
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f"b1[::] = {b1[::]} \n "
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f"b1[::2] = {b1[::2]} \n "
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f"b1[::-1] = {b1[::-1]} \n ")
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print( f"b2 = {b2} \n ")
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print(
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f"b2[0:-1] = {b2[0:-1]} \n "
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f"b2[0,-1] = {b2[0,-1]} \n "
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# 0可以不写。以下两个柿子结果不一样，在numpy中使用","做多维索引
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f"b2[0:2,0:3] = {b2[:2,:3]} \n "
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f"b2[:2][:3] = {b2[:2][:3]} \n "
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# 取第0行
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f"b2[0,:] = {b2[0,:]} \n "
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# 取第0列
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f"b2[:,0] = {b2[:,0]} \n "
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# 取最后1列
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f"b2[:,-1] = {b2[:,-1]} \n "
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# 行全取，列全取，行倒过来
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f"b2[::-1,::] = {b2[::-1,::]} \n "
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)
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