【Python】How to sort a 2D array by a column? - 101 Numpy Exercises
Q:
irisデータセットをsepallengthカラムの値でソートしなさい
A:
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') # Sort by column position 0: SepalLength print(iris[iris[:,0].argsort()][:20]) #> [[b'4.3' b'3.0' b'1.1' b'0.1' b'Iris-setosa'] #> [b'4.4' b'3.2' b'1.3' b'0.2' b'Iris-setosa'] #> [b'4.4' b'3.0' b'1.3' b'0.2' b'Iris-setosa'] #> [b'4.4' b'2.9' b'1.4' b'0.2' b'Iris-setosa']
