Python リストをNumPy配列ndarrayに変換: numpy.array()

NumPy配列ndarrayとPython標準のリストを相互に変換より
リストをNumPy配列ndarrayに変換: numpy.array()

import numpy as np

l_1d = [0, 1, 2]

arr_1d = np.array(l_1d)

print(arr_1d)
print(arr_1d.dtype)
# [0 1 2]
# int64

arr_1d_f = np.array(l_1d, dtype=float)

print(arr_1d_f)
print(arr_1d_f.dtype)
# [0. 1. 2.]
# float64

NumPy配列ndarrayをリストに変換: tolist()

import numpy as np

arr_1d = np.arange(3)

print(arr_1d)
# [0 1 2]

l_1d = arr_1d.tolist()

print(l_1d)
# [0, 1, 2]