{"id":5216,"date":"2021-05-10T09:32:14","date_gmt":"2021-05-10T04:02:14","guid":{"rendered":"https:\/\/python-programs.com\/?p=5216"},"modified":"2021-11-22T18:42:49","modified_gmt":"2021-11-22T13:12:49","slug":"convert-numpy-array-to-list-in-python","status":"publish","type":"post","link":"https:\/\/python-programs.com\/convert-numpy-array-to-list-in-python\/","title":{"rendered":"Convert NumPy array to list in python"},"content":{"rendered":"
In this article we are going to discuss about how we can convert a 1D or 2D or 3D Numpy Array to a list or list of lists.<\/p>\n
In Python, So, let’s see how it actually works.<\/p>\n We can use the same So, let’s see how it actually works.<\/p>\n We can also convert the 2D NumPy array to a flat list. For that first we have to convert the 2D NumPy array to 1D array by using So, let’s see how it actually works.<\/p>\n Similarly the 3D Numpy array can also be converted by using So, let’s see how it actually works.<\/p>\n The process is same like how we converted the 2D Numpy array to flatten list. Similarly, use the So, let’s see how it actually works.<\/p>\nndarray class<\/code> of Numpy Module provides
tolist()<\/code> function which can be used to convert a 1D array to list. All the elements of the 1D array will be contained as the items of the list.<\/p>\n
# Program :\r\n\r\nimport numpy as np\r\n# NumPy array created\r\narr = np.array([1, 2, 3, 4, 5])\r\n# Printing the NumPy array\r\nprint('Numpy Array:', arr)\r\n\r\n# Converting 1D Numpy Array to list\r\nnum_list = arr.tolist()\r\n\r\n# Printing the list\r\nprint('List: ', num_list)\r\n<\/pre>\n
Outptut :\r\nNumpy Array: <\/span>[<\/span>1<\/span> 2<\/span> 3<\/span> 4<\/span> 5<\/span>] <\/span>\r\nList: <\/span>[1<\/span>, <\/span>2<\/span>, <\/span>3<\/span>, <\/span>4<\/span>, <\/span>5<\/span>]<\/span><\/pre>\n
Converting 2D Numpy array to list of lists :<\/h3>\n
tolist()<\/code> function to convert the 2D Numpy array to list of lists i.e called as Nested List.<\/p>\n
# Program :\r\n\r\nimport numpy as np\r\n# 2D Numpy Array created\r\narr = np.array([[11, 12, 13, 14],\r\n [15, 16, 17, 18],\r\n [19, 20, 21, 22]])\r\n# Printing 2D numpy array \r\nprint('2D Numpy Array:')\r\nprint(arr)\r\n\r\n# Converting Numpy Array to list of lists\r\nlist_of_lists = arr.tolist()\r\n\r\n#Printing the nested list\r\nprint('List of lists:')\r\nprint(list_of_lists)<\/pre>\n
Output :\r\n2D Numpy Array:\r\n[[11, 12, 13, 14], \r\n[15, 16, 17, 18], \r\n[19, 20, 21, 22]]\r\nList of lists:<\/pre>\n
Converting 2D Numpy Array to a flattened list :<\/h3>\n
flatten()<\/code> function. Then convert 1D array to list by using
tolist()<\/code> function.<\/p>\n
# Program :\r\n\r\nimport numpy as np\r\n# 2D Numpy Array created\r\narr = np.array([[1, 2, 3, 4],\r\n [5, 6, 7, 8],\r\n [3, 3, 3, 3]])\r\n# Printing 2D Numpy array \r\nprint('2D Numpy Array:')\r\nprint(arr)\r\n\r\n# Converting 2D Numpy array toa single list\r\nnum_list = arr.flatten().tolist()\r\n\r\n#Printing list\r\nprint('List:', num_list)<\/pre>\n
Output :\r\n2D Numpy Array:\r\n[[1, 2, 3, 4], \r\n[5, 6, 7, 8], \r\n[3, 3, 3, 3]]\r\n2D Numpy Array:\r\n[1, 2, 3, 4, 5, 6, 7, 8, 3, 3, 3, 3]<\/pre>\n
Convert 3D Numpy array to nested list :<\/h3>\n
tolist()<\/code> function into list of nested lists.<\/p>\n
# Program :\r\n\r\nimport numpy as np\r\n\r\n# 3D Numpy Array created\r\narr = np.ones( (2,4,5) , dtype=np.int64)\r\n\r\n#Prinitng 3D Numpy array \r\nprint('3D Numpy Array:')\r\nprint(arr)\r\n\r\n# Converting 3D Numpy Array to nested list\r\nnested_list = arr.tolist()\r\n\r\n# Printing nested list\r\nprint('Nested list:')\r\nprint(nested_list)\r\n<\/pre>\n
Output :\r\n3D Numpy Array:<\/span>\r\n[[[<\/span>1<\/span> 1<\/span> 1<\/span> 1<\/span> 1<\/span>]<\/span>\r\n[<\/span>1<\/span> 1<\/span> 1<\/span> 1<\/span> 1<\/span>]<\/span>\r\n[<\/span>1<\/span> 1<\/span> 1<\/span> 1<\/span> 1<\/span>]<\/span>\r\n[<\/span>1<\/span> 1<\/span> 1<\/span> 1<\/span> 1<\/span>]]<\/span>\r\n\r\n\r\n[[<\/span>1<\/span> 1<\/span> 1<\/span> 1<\/span> 1<\/span>]<\/span>\r\n[<\/span>1<\/span> 1<\/span> 1<\/span> 1<\/span> 1<\/span>]<\/span>\r\n[<\/span>1<\/span> 1<\/span> 1<\/span> 1<\/span> 1<\/span>]<\/span>\r\n[<\/span>1<\/span> 1<\/span> 1<\/span> 1<\/span> 1<\/span>]]]<\/span>\r\nNested list:<\/span>\r\n[[[<\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>]<\/span>,<\/span>\r\n[<\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>]<\/span>,<\/span>\r\n[<\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>]<\/span>,<\/span>\r\n[<\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>]]<\/span>,<\/span>\r\n[[<\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>]<\/span>,<\/span>\r\n[<\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>]<\/span>,<\/span>\r\n[<\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>, <\/span>1<\/span>]<\/span>, <\/span>\r\n[<\/span>1<\/span>, 1<\/span>, 1<\/span>, 1<\/span>, 1<\/span>]]]<\/span><\/span><\/pre>\n
Converting 3D Numpy Array to a flat list :<\/h3>\n
flatten()<\/code> function to convert the 3D Numpy array to 1D array. Then convert the 1D Numpy array to flat list by using
tolist()<\/code> function.<\/p>\n
# Program :\r\n\r\nimport numpy as np\r\n# 3D Numpy Array created\r\narr = np.ones( (2,4,5) , dtype=np.int64)\r\n# Printing 3D Numpy array\r\nprint('3D Numpy Array:')\r\nprint(arr)\r\n\r\n# Converting 3D Numpy Array to flat list\r\nflat_list = arr.flatten().tolist()\r\n\r\n# Printing the list\r\nprint('Flat list:')\r\nprint(flat_list)<\/pre>\n
Output :<\/pre>\n