NumPy数组（1、数组初探）

目前我的工作是将NumPy引入到Pyston中（一款Dropbox实现的Python编译器/解释器）。在工作过程中，我深入接触了NumPy源码，了解其实现并提交了PR修复NumPy的bug。在与NumPy源码以及NumPy开发者打交道的过程中，我发现当今中文NumPy教程大部分都是翻译或参考英文文档，因此导致了许多疏漏。比如NumPy数组中的broadcast功能，几乎所有中文文档都翻译为“广播”。而NumPy的开发者之一，回复到“broadcast is a compound -- native English speakers can see that it's " broad" + "cast" = "cast (scatter, distribute) broadly, I guess "cast (scatter, distribute) broadly" probably is closer to the meaning（NumPy中的含义）"。有鉴于此，我打算启动一个项目，以我对NumPy使用以及源码层面的了解编写一个系列的教程。

地址随后会更新。CSDN的排版（列表）怎么显示不正常了。。。

NumPy数组

NumPy数组是一个多维数组对象，称为ndarray。其由两部分组成：

• 实际的数据
• 描述这些数据的元数据

大部分操作仅针对于元数据，而不改变底层实际的数据。

关于NumPy数组有几点必需了解的：

• NumPy数组的下标从0开始。
• 同一个NumPy数组中所有元素的类型必须是相同的。

NumPy数组属性

在详细介绍NumPy数组之前。先详细介绍下NumPy数组的基本属性。NumPy数组的维数称为秩（rank），一维数组的秩为1，二维数组的秩为2，以此类推。在NumPy中，每一个线性的数组称为是一个轴（axes），秩其实是描述轴的数量。比如说，二维数组相当于是两个一维数组，其中第一个一维数组中每个元素又是一个一维数组。所以一维数组就是NumPy中的轴（axes），第一个轴相当于是底层数组，第二个轴是底层数组里的数组。而轴的数量——秩，就是数组的维数。

NumPy的数组中比较重要ndarray对象属性有：

• ndarray.ndim：数组的维数（即数组轴的个数），等于秩。最常见的为二维数组（矩阵）。

• ndarray.shape：数组的维度。为一个表示数组在每个维度上大小的整数元组。例如二维数组中，表示数组的“行数”和“列数”。ndarray.shape返回一个元组，这个元组的长度就是维度的数目，即ndim属性。

• ndarray.size：数组元素的总个数，等于shape属性中元组元素的乘积。

• ndarray.dtype：表示数组中元素类型的对象，可使用标准的Python类型创建或指定dtype。另外也可使用前一篇文章中介绍的NumPy提供的数据类型。

• ndarray.itemsize：数组中每个元素的字节大小。例如，一个元素类型为float64的数组itemsiz属性值为8(float64占用64个bits，每个字节长度为8，所以64/8，占用8个字节），又如，一个元素类型为complex32的数组item属性为4（32/8）。

• ndarray.data：包含实际数组元素的缓冲区，由于一般通过数组的索引获取元素，所以通常不需要使用这个属性。

创建数组

<span style="font-size: 18px;">　　<span style="font-family: SimSun; font-size: 14px;"><span lang="zh-CN">先来介绍</span>创建数组。<span lang="zh-CN">创建数组的方法有很多。</span>如可以使用<span lang="en-US">array</span>函数从常规的<span lang="en-US">Python</span>列表和元组创造数组。所创建的数组类型由原序列中的元素类型推导而来。</span><span style="font-family: SimSun;">　　　</span></span><div class="dp-highlighter bg_python" style="font-family: Consolas, 'Courier New', Courier, mono, serif; font-size: 12px; width: 700.912px; overflow: auto; padding-top: 1px; margin: 18px 0px !important; background-color: rgb(231, 229, 220);"><div class="bar" style="padding-left: 45px;"><div class="tools" style="padding: 3px 8px 10px 10px; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Verdana, Geneva, Arial, Helvetica, sans-serif; color: silver; border-left-width: 3px; border-left-style: solid; border-left-color: rgb(108, 226, 108); background-color: rgb(248, 248, 248);"><strong>[python]</strong> <a target=_blank href="http://blog.csdn.net/sunny2038/article/details/9002531#" class="ViewSource" title="view plain" style="color: rgb(160, 160, 160); text-decoration: none; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-image: url("images/default/ico_plain.gif"); background-attachment: initial; background-color: inherit; background-size: initial; background-origin: initial; background-clip: initial; background-position: 0% 0%; background-repeat: no-repeat;">view plain</a><span data-mod="popu_168"> <a target=_blank href="http://blog.csdn.net/sunny2038/article/details/9002531#" class="CopyToClipboard" title="copy" style="color: rgb(160, 160, 160); text-decoration: none; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-image: url("images/default/ico_copy.gif"); background-attachment: initial; background-color: inherit; background-size: initial; background-origin: initial; background-clip: initial; background-position: 0% 0%; background-repeat: no-repeat;">copy</a></span><div style="position: absolute; left: 653px; top: 1912px; width: 18px; height: 18px; z-index: 99;"></div><span data-mod="popu_169"> </span></div></div><ol start="1" class="dp-py" style="padding: 0px; border: none; color: rgb(92, 92, 92); margin: 0px 0px 1px 45px !important; background-color: rgb(255, 255, 255);"><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">>>> </span><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); font-weight: bold; background-color: inherit;">from</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> numpy </span><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); font-weight: bold; background-color: inherit;">import</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> *  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　  </span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">>>> a = array( [<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">2</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">,</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">3</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">,</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">4</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">] )　　　  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">>>> a  </span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    array([<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">2</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">, </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">3</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">, </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">4</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">])  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">>>> a.dtype  </span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    dtype(<span class="string" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">'int32'</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">)  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">>>> b = array([<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">1.2</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">, </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">3.5</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">, </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">5.1</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">])　　　  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">>>> b.dtype  </span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    dtype(<span class="string" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">'float64'</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">)  </span></span></li></ol></div>

使用array函数创建时，参数必须是由方括号括起来的列表，而不能使用多个数值作为参数调用array。　　　

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1. >>> a = array(1,2,3,4)    # 错误  
2. >>> a = array([1,2,3,4])  # 正确  

可使用双重序列来表示二维的数组，三重序列表示三维数组，以此类推。

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1. >>> b = array( [ (1.5,2,3), (4,5,6) ] )　　  
2. >>> b  
3.     array([[ 1.5,  2. ,  3. ],  
4. 　　　     [ 4. ,  5. ,  6. ]])  

可以在创建时显式指定数组中元素的类型

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1. >>> c = array( [ [1,2], [3,4] ], dtype=complex)  
2. >>> c  
3.     array([[ 1.+0.j,  2.+0.j],  
4. 　　　    [ 3.+0.j,  4.+0.j]])  

通常，刚开始时数组的元素未知，而数组的大小已知。因此，NumPy提供了一些使用占位符创建数组的函数。这些函数有助于满足除了数组扩展的需要，同时降低了高昂的运算开销。

用函数zeros可创建一个全是0的数组，用函数ones可创建一个全为1的数组，函数empty创建一个内容随机并且依赖与内存状态的数组。默认创建的数组类型(dtype)都是float64。

可以哟娜特d.dtype.itemsize来查看数组中元素占用的字节数目。

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1. >>> d = zeros((3,4))  
2. >>> d.dtype  
3. dtype('float64')  
4. >>> d  
5. array([[ 0.,  0.,  0.,  0.],  
6. 　　   [ 0.,  0.,  0.,  0.],  
7. 　　   [ 0.,  0.,  0.,  0.]])  
8. >>> d.dtype.itemsize  
9. 8  

也可以自己制定数组中元素的类型

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1. >>> ones( (2,3,4), dtype=int16 )  #手动指定数组中元素类型  
2.       array([[[1, 1, 1, 1],  
3. 　　　        [1, 1, 1, 1],  
4. 　　　        [1, 1, 1, 1]],  
5. 　　　  
6. 　　　       [[1, 1, 1, 1],  
7. 　　　        [1, 1, 1, 1],  
8. 　　　        [1, 1, 1, 1]]], dtype=int16)  
9. >>> empty((2,3))  
10. 　　　array([[  2.65565858e-316,   0.00000000e+000,   0.00000000e+000],  
11. 　　　       [  0.00000000e+000,   0.00000000e+000,   0.00000000e+000]])  

NumPy提供一个类似arange的函数返回一个数列形式的数组:

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1. >>> arange(10, 30, 5)  
2.     array([10, 15, 20, 25])  

以10开始，差值为5的等差数列。该函数不仅接受整数，还接受浮点参数：　

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1. >>> arange(0,2,0.5)  
2.     array([ 0. ,  0.5,  1. ,  1.5])  

当arange使用浮点数参数时，由于浮点数精度有限，通常无法预测获得的元素个数。因此，最好使用函数linspace去接收我们想要的元素个数来代替用range来指定步长。linespace用法如下，将在通用函数一节中详细介绍。

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1. >>> numpy.linspace(-1, 0, 5)  
2.         array([-1.  , -0.75, -0.5 , -0.25,  0.  ])  

数组中的元素是通过下标来访问的，可以通过方括号括起一个下标来访问数组中单一一个元素，也可以以切片的形式访问数组中多个元素。关于切片访问，将在切片一节介绍。

知识点：NumPy中的数据类型
对于科学计算来说，Python中自带的整型、浮点型和复数类型远远不够，因此NumPy中添加了许多数据类型。如下：

NumPy中的基本数据类型名称描述bool用一个字节存储的布尔类型（True或False）inti由所在平台决定其大小的整数（一般为int32或int64）int8一个字节大小，-128 至 127int16整数，-32768 至 32767int32整数，-2 ** 31 至 2 ** 32 -1int64整数，-2 ** 63 至 2 ** 63 - 1uint8无符号整数，0 至 255uint16无符号整数，0 至 65535uint32无符号整数，0 至 2 ** 32 - 1uint64无符号整数，0 至 2 ** 64 - 1float16半精度浮点数：16位，正负号1位，指数5位，精度10位float32单精度浮点数：32位，正负号1位，指数8位，精度23位float64或float双精度浮点数：64位，正负号1位，指数11位，精度52位complex64复数，分别用两个32位浮点数表示实部和虚部complex128或complex复数，分别用两个64位浮点数表示实部和虚部

NumPy类型转换方式如下：

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1. >>> float64(42)  
2.     42.0  
3. >>> int8(42.0)  
4.     42  
5. >>> bool(42)  
6.     True  
7. >>> bool(42.0)  
8.     True  
9. >>> float(True)  
10.     1.0  

许多函数的参数中可以指定参数的类型，当然，这个类型参数是可选的。如下：

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1. >>> arange(7, dtype=uint16)  
2.     array([0, 1, 2, 3, 4, 5, 6], dtype=uint16)  

输出数组

<span style="font-size: 18px;">    <span style="font-size: 14px;">当输出一个数组时，<span style="font-family: 'Courier New', monospace;"><span lang="en-US">NumPy</span></span>以特定的布局用类似嵌套列表的形式显示：</span></span>

• 第一行从左到右输出
• 每行依次自上而下输出
• 每个切片通过一个空行与下一个隔开
• 一维数组被打印成行，二维数组成矩阵，三维数组成矩阵列表。

<span style="font-size: 18px;"> 　　　</span><div class="dp-highlighter bg_python" style="font-family: Consolas, 'Courier New', Courier, mono, serif; font-size: 12px; width: 700.912px; overflow: auto; padding-top: 1px; margin: 18px 0px !important; background-color: rgb(231, 229, 220);"><div class="bar" style="padding-left: 45px;"><div class="tools" style="padding: 3px 8px 10px 10px; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Verdana, Geneva, Arial, Helvetica, sans-serif; color: silver; border-left-width: 3px; border-left-style: solid; border-left-color: rgb(108, 226, 108); background-color: rgb(248, 248, 248);"><strong>[python]</strong> <a target=_blank href="http://blog.csdn.net/sunny2038/article/details/9002531#" class="ViewSource" title="view plain" style="color: rgb(160, 160, 160); text-decoration: none; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-image: url("images/default/ico_plain.gif"); background-attachment: initial; background-color: inherit; background-size: initial; background-origin: initial; background-clip: initial; background-position: 0% 0%; background-repeat: no-repeat;">view plain</a><span data-mod="popu_168"> <a target=_blank href="http://blog.csdn.net/sunny2038/article/details/9002531#" class="CopyToClipboard" title="copy" style="color: rgb(160, 160, 160); text-decoration: none; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-image: url("images/default/ico_copy.gif"); background-attachment: initial; background-color: inherit; background-size: initial; background-origin: initial; background-clip: initial; background-position: 0% 0%; background-repeat: no-repeat;">copy</a></span><div style="position: absolute; left: 653px; top: 5163px; width: 18px; height: 18px; z-index: 99;"></div><span data-mod="popu_169"> </span></div></div><ol start="1" class="dp-py" style="padding: 0px; border: none; color: rgb(92, 92, 92); margin: 0px 0px 1px 45px !important; background-color: rgb(255, 255, 255);"><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">>>> a = arange(</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">6</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">)                         </span><span class="comment" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 130, 0); background-color: inherit;"># 1d array</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">>>> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); font-weight: bold; background-color: inherit;">print</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> a  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    [<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">0</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">1</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">2</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">3</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">4</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">5</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　  </span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">>>> b = arange(<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">12</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">).reshape(</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">4</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">,</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">3</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">)           </span><span class="comment" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 130, 0); background-color: inherit;"># 2d array</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">>>> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); font-weight: bold; background-color: inherit;">print</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> b  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    [[ <span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">0</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">1</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">2</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    [ <span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">3</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">4</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">5</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    [ <span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">6</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">7</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">8</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    [ <span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">10</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">11</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]]　　　  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">>>> c = arange(<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">24</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">).reshape(</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">2</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">,</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">3</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">,</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">4</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">)         </span><span class="comment" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 130, 0); background-color: inherit;"># 3d array</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">>>> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); font-weight: bold; background-color: inherit;">print</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> c  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    [[[ <span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">0</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">1</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">2</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">3</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    [ <span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">4</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">5</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">6</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">7</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    [ <span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">8</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">10</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">11</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]]  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　  </span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    [[<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">12</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">13</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">14</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">15</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    [<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">16</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">17</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">18</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">19</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">    [<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">20</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">21</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">22</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">23</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]]]  </span></span></li></ol></div><span style="font-size: 18px;"><span style="font-size: 14px;"><span style="font-family: SimSun;">    <span lang="en-US">reshape</span>将在下一篇文章中介绍　    如果一个数组太长，则<span lang="en-US">NumPy</span>自动省略中间部分而只打印两端的数据：　　</span>　</span></span><div class="dp-highlighter bg_python" style="font-family: Consolas, 'Courier New', Courier, mono, serif; font-size: 12px; width: 700.912px; overflow: auto; padding-top: 1px; margin: 18px 0px !important; background-color: rgb(231, 229, 220);"><div class="bar" style="padding-left: 45px;"><div class="tools" style="padding: 3px 8px 10px 10px; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Verdana, Geneva, Arial, Helvetica, sans-serif; color: silver; border-left-width: 3px; border-left-style: solid; border-left-color: rgb(108, 226, 108); background-color: rgb(248, 248, 248);"><strong>[python]</strong> <a target=_blank href="http://blog.csdn.net/sunny2038/article/details/9002531#" class="ViewSource" title="view plain" style="color: rgb(160, 160, 160); text-decoration: none; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-image: url("images/default/ico_plain.gif"); background-attachment: initial; background-color: inherit; background-size: initial; background-origin: initial; background-clip: initial; background-position: 0% 0%; background-repeat: no-repeat;">view plain</a><span data-mod="popu_168"> <a target=_blank href="http://blog.csdn.net/sunny2038/article/details/9002531#" class="CopyToClipboard" title="copy" style="color: rgb(160, 160, 160); text-decoration: none; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-image: url("images/default/ico_copy.gif"); background-attachment: initial; background-color: inherit; background-size: initial; background-origin: initial; background-clip: initial; background-position: 0% 0%; background-repeat: no-repeat;">copy</a></span><div style="position: absolute; left: 653px; top: 5618px; width: 18px; height: 18px; z-index: 99;"></div><span data-mod="popu_169"> </span></div></div><ol start="1" class="dp-py" style="padding: 0px; border: none; color: rgb(92, 92, 92); margin: 0px 0px 1px 45px !important; background-color: rgb(255, 255, 255);"><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">>>> </span><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); font-weight: bold; background-color: inherit;">print</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> arange(</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">10000</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">)  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　[   <span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">0</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">    </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">1</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">    </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">2</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> ..., </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9997</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9998</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9999</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　  </span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">>>> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); font-weight: bold; background-color: inherit;">print</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> arange(</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">10000</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">).reshape(</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">100</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">,</span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">100</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">)  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　[[   <span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">0</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">    </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">1</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">    </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">2</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> ...,   </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">97</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">   </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">98</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">   </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">99</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　 [ <span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">100</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">101</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">102</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> ...,  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">197</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">198</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">199</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　 [ <span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">200</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">201</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">202</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> ...,  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">297</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">298</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">  </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">299</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　 ...,  </span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　 [<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9700</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9701</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9702</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> ..., </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9797</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9798</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9799</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important; background-color: rgb(248, 248, 248);"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　 [<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9800</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9801</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9802</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> ..., </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9897</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9898</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9899</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]  </span></span></li><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">　　　 [<span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9900</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9901</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9902</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> ..., </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9997</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9998</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="number" style="margin: 0px; padding: 0px; border: none; background-color: inherit;">9999</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">]]  </span></span></li></ol></div><span style="font-size: 18px;"><span style="font-size: 14px;">　　可通过</span></span><span style="font-size: 18px;"><span style="font-size: 14px;">设置<span style="font-family: 'Courier New', monospace;"><span lang="en-US">printoptions</span></span>参数来</span></span><span style="font-size: 18px;"><span style="font-size: 14px;">禁用<span style="font-family: 'Courier New', monospace;"><span lang="en-US">NumPy</span></span>的这种行为并强制打印整个数组。</span></span><pre class="cjk" name="code" style="white-space: pre-wrap; word-wrap: break-word;"><div class="dp-highlighter bg_python" style="font-family: Consolas, 'Courier New', Courier, mono, serif; font-size: 12px; width: 700.912px; overflow: auto; padding-top: 1px; margin: 18px 0px !important; background-color: rgb(231, 229, 220);"><div class="bar" style="padding-left: 45px;"><div class="tools" style="padding: 3px 8px 10px 10px; font-stretch: normal; font-size: 9px; line-height: normal; font-family: Verdana, Geneva, Arial, Helvetica, sans-serif; color: silver; border-left-width: 3px; border-left-style: solid; border-left-color: rgb(108, 226, 108); background-color: rgb(248, 248, 248);"><strong>[python]</strong> <a target=_blank href="http://blog.csdn.net/sunny2038/article/details/9002531#" class="ViewSource" title="view plain" style="color: rgb(160, 160, 160); text-decoration: none; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-image: url("images/default/ico_plain.gif"); background-attachment: initial; background-color: inherit; background-size: initial; background-origin: initial; background-clip: initial; background-position: 0% 0%; background-repeat: no-repeat;">view plain</a><span data-mod="popu_168"> <a target=_blank href="http://blog.csdn.net/sunny2038/article/details/9002531#" class="CopyToClipboard" title="copy" style="color: rgb(160, 160, 160); text-decoration: none; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-image: url("images/default/ico_copy.gif"); background-attachment: initial; background-color: inherit; background-size: initial; background-origin: initial; background-clip: initial; background-position: 0% 0%; background-repeat: no-repeat;">copy</a></span><div style="position: absolute; left: 653px; top: 5933px; width: 18px; height: 18px; z-index: 99;"></div><span data-mod="popu_169"> </span></div></div><ol start="1" class="dp-py" style="padding: 0px; border: none; color: rgb(92, 92, 92); margin: 0px 0px 1px 45px !important; background-color: rgb(255, 255, 255);"><li class="alt" style="border-left-width: 3px; border-style: none none none solid; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">set_printoptions(threshold=</span><span class="string" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">'nan'</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">)  </span></span></li></ol></div><span style="font-size: 18px;"><span id="_xhe_cursor"></span><span style="font-family: 'Courier New', monospace;"><span lang="en-US"></span></span></span>

这样，输出时数组的所有元素都会显示出来。

未完待续，如有错误，敬请指正！

参考文献：

《NumPy for Beginner》
《Python科学计算》
《Tentative NumPy Tutorial》