## Numpy Array Create ### Import Required Module Numpy and Rename ```python import numpy as np ``` #### Numpy Array Using List ```python #Define Simple List lst=[10,23,2,3,7,8] #Create numpy array using lst np_array=np.array(lst) #print numpy array print("Create Numpy Array Using List:\n",np_array) ``` Output: Create Numpy Array Using List: [10 23 2 3 7 8] #### Numpy Array Using Tuple ```python #Define Simple Tuple tple=(10,23,2,3,7,8) #Create numpy array using tuple np_array=np.array(tple) #print numpy array print("Create a Numpy Array Using Tuple:\n",np_array) ``` Output: Create a Numpy Array Using Tuple: [10 23 2 3 7 8] #### Numpy String Array ```python tple=np.array(['P','Y','T','H','O','N']) #Create numpy array using tuple np_array=np.array(tple) #print numpy array print("Create Numpy Array Using Characters :\n",np_array) ``` Output: Create Numpy Array Using Characters : ['P' 'Y' 'T' 'H' 'O' 'N'] #### Create Numpy array using arange() function ```python #Simple Array Here Only End is Specified arr=np.arange(6) print("Array With stop Parameter: ",arr) print("Type of an Array: ",arr.dtype) #Create Float Array arr=np.arange(6.0) print("\nArray With stop Parameter: ",arr) print("Type of an Array: ",arr.dtype) #Numpy Array From Specific Range arr=np.arange(4,9) #it will include 4 and exclude 9 print("\nArray With Specified Range: ",arr) print("Type of an Array: ",arr.dtype) #Simple Numpy array with Step counter(print 5 table) arr=np.arange(5,51,5) print("\nArray of 5 Table: ",arr) print("Type of an Array: ",arr.dtype) ``` Output: Array With stop Parameter: [0 1 2 3 4 5] Type of an Array: int32 Array With stop Parameter: [0. 1. 2. 3. 4. 5.] Type of an Array: float64 Array With Specified Range: [4 5 6 7 8] Type of an Array: int32 Array of 5 Table: [ 5 10 15 20 25 30 35 40 45 50] Type of an Array: int32 ## important Terminologies Used In Numpy array ```python #Simple list lst=[1,2,3] np_ar=np.array(lst) ``` #### Print The Numpy Array ```python # print Normal numpy array print(np_ar) ``` Output: [1 2 3] #### Get Shape of Numpy array Use the following syntax to get the shape of numpy array numpy_array.shape ```python #This is 1d Array So Only shape=np_ar.shape print("Shape Of an Array(row,columns):",shape) ``` Output: Shape Of an Array(row, columns): (3,) #### Get element data types in numpy array numpy_array.dtype ```python data_type=np_ar.dtype print("Data Type Of Numpy Array:",data_type) ``` Output: Data Type Of Numpy Array: int32 #### Get Dimension Of Numpy Array - To get the Dimension of numpy array simple call *ndim* with numpy array numpy_array.ndim ```python dim=np_ar.ndim print("The dimension of the Numpy Array:",dim) ``` Output: The dimension of the Numpy Array: 1 #### Get Element Count(Size How many Element in numpy array) - To simply get the Count of the present element in the numpy array use *size* as follows numpy_array.size ```python elem_count=np_ar.size print("Element Count:",elem_count) ``` Output: Element Count: 3 #### Get the element Size in Bytes ```python size=np_ar.itemsize print("Item Size in Bytes:",size) ``` Output: Item Size in Bytes: 4 ## Type Of Numpy Array ``` 1. Single Dimensional 2. Two Dimensional 3. Three Dimensional ``` ### 1. Single Dimensional ![1d](https://github.com/chavarera/PythonScript/blob/master/MachineLearning/Numpy/img/np1d.png) ```python import numpy as np #Simple list lst=[1,2,3,4] np_1d=np.array(lst) print("1D Numpy Array:\n",np_1d) #dimensssions print("\nDimenssion of np_1d: ",np_1d.ndim) #Second value from tuple is blank for shape becaue it is 1d array print("Shape Of Array(row,colums) :",np_1d.shape) #Get Type of Array Elements print("Type Of Numpy Array Elements : ",np_1d.dtype) #get Item Size print("Item Size: ",np_1d.itemsize) #get objects Size print("Object Size: ",np_1d.size) ``` Output: 1D Numpy Array: [1 2 3 4] Dimenssion of np_1d: 1 Shape Of Array(row,colums) : (4,) Type Of Numpy Array Elements : int32 Item Size: 4 Object Size: 4 ### 2.Two Dimensssional ![2d](https://github.com/chavarera/PythonScript/blob/master/MachineLearning/Numpy/img/np2d.png) ```python import numpy as np #2d List lst2=[ [1,2], [3,4], [5,6] ] np_2d=np.array(lst2) print("2D Numpy Array:\n",np_2d) #dimensssions print("\nDimenssion of np_2d: ",np_2d.ndim) #three rows 2 columns print("Shape Of Array(row,colums) :",np_2d.shape) #Get Type of Array Elements print("Type Of Numpy Array Elements : ",np_2d.dtype) #get Item Size print("Size of Object Size: ",np_2d.itemsize) #get objects Size print("element Count : ",np_2d.size) ``` Output: 2D Numpy Array: [[1 2] [3 4] [5 6]] Dimenssion of np_2d: 2 Shape Of Array(row,colums) : (3, 2) Type Of Numpy Array Elements : int32 Size of Object Size: 4 element Count : 6 ### 3. Three dimensional ![3d](https://github.com/chavarera/PythonScript/blob/master/MachineLearning/Numpy/img/np3d.png) ```python import numpy as np #3d List lst3=[ [ [3,4,5], [6,7,8], [9,10,11] ], [ [0,1,2], [12,13,14], [15,16,17] ], [ [18,19,20], [21,22,23], [24,25,27] ] ] np_3d=np.array(lst3) print(np_3d) #dimensssions print("\nDimenssion of np_3d: ",np_3d.ndim) #three rows 2 columns print("Shape Of Array(row,colums) :",np_3d.shape) #Get Type of Array Elements print("Type Of Numpy Array Elements : ",np_3d.dtype) #get Item Size print("Size of Object Size: ",np_3d.itemsize) #get objects Size print("Element Count: ",np_3d.size) ``` Output [[[ 3 4 5] [ 6 7 8] [ 9 10 11]] [[ 0 1 2] [12 13 14] [15 16 17]] [[18 19 20] [21 22 23] [24 25 27]]] Dimenssion of np_3d: 3 Shape Of Array(row,colums) : (3, 3, 3) Type Of Numpy Array Elements : int32 Size of Object Size: 4 Element Count: 27