打印格式化numpy数组

Question

我想打印格式化numpy数组以及具有不同有效数字的浮点数。考虑下面的代码

a = 3.14159
X = np.array([1.123, 4.456, 7.789])
print('a = %4.3f, X = %3.2f' % (a, X))
------------------------
TypeError: only size-1 arrays can be converted to Python scalars

我想要以下输出-

a = 3.141, X = [1.12, 4.45, 7.78]

建议修改代码

Answer 1

您可以使用np.set_printoptions(precision=2):

import numpy as np
a = 3.14159
X = np.array([1.123, 4.456, 7.789])
np.set_printoptions(precision=2)
print(f'{a = :4.3f}, X = {X}')

输出

a = 3.142, X = [1.12 4.46 7.79]

Answer 2

先用array2string:

将数组转换为字符串

print('a = %4.3f, X = %s' % (a, np.array2string(X, precision=2)))
# a = 3.142, X = [1.12 4.46 7.79]