In this article we will discuss about different ways to \u00a0check if all values in a numpy array are 0 i.e in both 1D and 2D arrays.<\/p>\n
So let’s start exploring the topic.<\/p>\n
In this method we will check that each element of the array will be compared with the particular element i.e zero. And a a result it will return a bool array containing True or False.<\/p>\n
# program :\r\n\r\nimport numpy as np\r\n\r\n# 1D numpy array created from a list\r\narr = np.array([0, 0, 0, 0, 0, 0])\r\n\r\n# Checking if all elements in array are zero\r\ncheck_zero = np.all((arr == 0))\r\nif check_zero:\r\n print('All the elements of array are zero')\r\nelse:\r\n print('All the elements of the array are not zero')<\/pre>\nOutput :\r\nAll the elements of array are zero<\/pre>\nMethod 2: Using numpy.any() to check if a 1D Numpy array contains only 0 :<\/h3>\n
We can use the numpy.any()<\/code> function to check that if the array contains only zeros by looking for any non zero value. All the elements received by numpy.any()<\/code> function gets typecast to bool values i.e. 0 to False and others as True. So if all the values in the array are zero then it will return False and then by using not<\/code> we can confirm our array contains only zeros or not.<\/p>\n# program :\r\n\r\nimport numpy as np\r\n\r\n# 1D numpy array created from a list\r\narr = np.array([0, 0, 0, 0, 0, 0])\r\n\r\n# Checking if all elements in array are zero\r\ncheck_zero = not np.any(arr)\r\nif check_zero:\r\n print('All the elements of array are zero')\r\nelse:\r\n print('All the elements of the array are not zero')<\/pre>\nOutput : \r\nAll the elements of array are zero<\/pre>\nMethod 3: Using numpy.count_nonzero() to check if a 1D Numpy array contains only 0 :<\/h3>\n
numpy.count_nonzero()<\/code>\u00a0 function returns a count of non-zero values in the array. So by using it we can check if the array contains any non zero value or not. If any non zero element found in the array then all the elements of the array are not zero and if no non zero value found then then all the elements in the array are zero.<\/p>\n# program :\r\n\r\nimport numpy as np\r\n\r\n# 1D numpy array created from a list\r\narr = np.array([0, 0, 0, 0, 0, 0])\r\n\r\n# Checking if all elements in array are zero\r\n# Count non zero items in array\r\ncount_non_zeros = np.count_nonzero(arr)\r\nif count_non_zeros==0:\r\n print('All the elements of array are zero')\r\nelse:\r\n print('All the elements of the array are not zero')<\/pre>\nOutput :\r\nAll the elements of array are zero<\/pre>\nMethod 4: Using for loop to check if a 1D Numpy array contains only 0 :<\/h3>\n
By iterating over all the elements of the array we also check that array contains only zeros or not.<\/p>\n
# program :\r\n\r\nimport numpy as np\r\n\r\n# 1D numpy array created from a list\r\narr = np.array([0, 0, 0, 0, 0, 0])\r\n\r\n# Checking if all elements in array are zero\r\ndef check_zero(arr):\r\n # iterating of the array\r\n # and checking if any element is not equal to zero\r\n for elem in arr:\r\n if elem != 0:\r\n return False\r\n return True\r\nresult = check_zero(arr)\r\n\r\nif result:\r\n print('All the elements of array are zero')\r\nelse:\r\n print('All the elements of the array are not zero')<\/pre>\nOutput :\r\nAll the elements of array are zero<\/pre>\nMethod 5: Using List Comprehension to check if a 1D Numpy array contains only 0 :<\/h3>\n
By using List Comprehension also we can iterate over each element in the numpy array and then we can create a list of values which are non zero.And if the list contains any element then we can confirm all the values of the numpy array were not zero.<\/p>\n
# program :\r\n\r\nimport numpy as np\r\n\r\n# 1D numpy array created from a list\r\narr = np.array([0, 0, 0, 0, 0, 0])\r\n\r\n# Iterating over each element of array \r\n# And create a list of non zero items from array\r\nresult = len([elem for elem in arr if elem != 0])\r\n# from this we can knoew that if our list contains no element then the array contains all zero values.\r\n\r\nif result==0:\r\n print('All the elements of array are zero')\r\nelse:\r\n print('All the elements of the array are not zero')<\/pre>\nOutput :\r\nAll the elements of array are zero<\/pre>\nMethod 6: Using min() and max() to check if a 1D Numpy array contains only 0 :<\/h3>\n
If the minimum and maximum value in the array are same and i.e zero then we can confirm the array contains only zeros.<\/p>\n
# program :\r\n\r\nimport numpy as np\r\n\r\n# 1D numpy array created from a list\r\narr = np.array([0, 0, 0, 0, 0, 0])\r\n\r\nif arr.min() == 0 and arr.max() == 0:\r\n print('All the elements of array are zero')\r\nelse:\r\n print('All\u00a0the\u00a0elements\u00a0of\u00a0the\u00a0array\u00a0are\u00a0not\u00a0zero')<\/pre>\nOutput :\r\nAll the elements of array are zero<\/pre>\nCheck if all elements in a 2D numpy array or matrix are zero :<\/h3>\n