Numpy (39)

How to find the count of unique values in a numpy array?

# Import iris keeping the text column intact
url = 'https://archive.ics.uci.edu/ml/machine-learning-databases/iris/iris.data'
iris = np.genfromtxt(url, delimiter=',', dtype='object')
names = ('sepallength', 'sepalwidth', 'petallength', 'petalwidth', 'species')

# Solution
# Extract the species column as an array
species = np.array([row.tolist()[4] for row in iris])

# Get the unique values and the counts
np.unique(species, return_counts=True)

# output
(array([b'Iris-setosa', b'Iris-versicolor', b'Iris-virginica'],
        dtype='|S15'), array([50, 50, 50]))