Jupyter notebook中运行代码，代码运行没问题却出现警告。

源码：

#阶跃函数
import numpy as np
import matplotlib.pylab as plt

def step_function(x):
       return np.array(x > 0, dtype = np.int)  #重点关注
x = np.arange(-5.0, 5.0, 0.1)
y = step_function(x)
plt.plot(x, y)
plt.ylim(-0.1, 1.1)
plt.show()

警告：

:6: DeprecationWarning: `np.int` is a deprecated alias for the builtin `int`. To silence this warning, use `int` by itself. Doing this will not modify any behavior and is safe. When replacing `np.int`, you may wish to use e.g. `np.int64` or `np.int32` to specify the precision. If you wish to review your current use, check the release note link for additional information.
Deprecated in NumPy 1.20; for more details and guidance: NumPy 1.20.0 Release Notes — NumPy v1.22.dev0 Manual
  return np.array(x > 0, dtype = np.int)

分析：

简单的说，就是当前的Numpy版本希望你将np.int格式改为np.int64或np.int32的格式。如果不换的话也不影响，但是每次运行代码时，警告也会随之出现。