如何解决导入mxnet时出现的‘module 'numpy' has no attribute 'bool'’错误？

问题场景 #

我在Google Colab中尝试用Python 3.8.5运行import mxnet as mx时，出现了module 'numpy' has no attribute 'bool'的错误。这段代码在2023年12月和2024年1月都能正常运行，现在突然无法使用了。我的操作步骤和代码如下：

挂载Google Drive #

from google.colab import drive
drive.mount('/content/drive')

安装Python 3.8.5 #

!wget https://www.python.org/ftp/python/3.8.5/Python-3.8.5.tgz
!tar xvfz Python-3.8.5.tgz
!Python-3.8.5/configure
!make
!sudo make install

安装依赖包 #

!pip install torch==1.6.0+cpu torchvision==0.7.0+cpu -f https://download.pytorch.org/whl/torch_stable.html
!pip install --upgrade gluoncv
!pip install --upgrade mxnet

导入模块的代码 #

import mxnet as mx
from mxnet import image
from mxnet.gluon.data.vision import transforms

import gluoncv
from gluoncv.utils.viz import get_color_pallete
import matplotlib.image as mpimg
from gluoncv.data.ade20k.segmentation import ADE20KSegmentation
from matplotlib import pyplot as plt
from gluoncv.data.transforms.presets.segmentation import test_transform
from google.colab import files

import pandas as pd
import numpy as np
import os

报错信息 #

/usr/local/lib/python3.10/dist-packages/mxnet/numpy/utils.py:37: FutureWarning: In the future `np.bool` will be defined as the corresponding NumPy scalar.
  bool = onp.bool
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-6-d07a1bcfa66c> in <cell line: 1>()
----> 1 import mxnet as mx
      2 from mxnet import image
      3 from mxnet.gluon.data.vision import transforms
      4 import gluoncv
      5 

7 frames
/usr/local/lib/python3.10/dist-packages/numpy/__init__.py in __getattr__(attr)
    317 
    318         if attr in __former_attrs__:
--> 319             raise AttributeError(__former_attrs__[attr])
    320 
    321         if attr == 'testing':

AttributeError: module 'numpy' has no attribute 'bool'.
`np.bool` was a deprecated alias for the builtin `bool`. To avoid this error in existing code, use `bool` by itself. Doing this will not modify any behavior and is safe. If you specifically wanted the numpy scalar type, use `np.bool_` here.
The aliases was originally deprecated in NumPy 1.20; for more details and guidance see the original release note at:
    https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations

解决方法 #

方法1：锁定兼容的numpy版本 #

问题核心是新版numpy彻底移除了np.bool这个废弃别名，而当前安装的mxnet版本仍在使用该写法。安装numpy 1.23.x及以下版本（保留np.bool兼容支持）即可解决：

!pip install numpy==1.23.5

执行后重新导入mxnet即可。

方法2：修改mxnet源码兼容新版numpy #

如果不想降低numpy版本，可直接修改mxnet的兼容代码：找到报错中提示的/usr/local/lib/python3.10/dist-packages/mxnet/numpy/utils.py文件，将第37行的bool = onp.bool修改为：

bool = onp.bool_
# 或直接使用内置类型：bool = bool

注意：Colab重启后该修改会失效，仅适合临时测试。

方法3：确保Python 3.8环境生效 #

手动安装Python 3.8.5后，Colab默认仍使用系统Python 3.10，导致依赖包安装到了错误环境。用以下命令强制在Python 3.8环境中安装依赖：

!python3.8 -m pip install torch==1.6.0+cpu torchvision==0.7.0+cpu -f https://download.pytorch.org/whl/torch_stable.html
!python3.8 -m pip install --upgrade gluoncv
!python3.8 -m pip install --upgrade mxnet numpy==1.23.5

运行代码前切换Python环境：

import sys
sys.executable = '/usr/local/bin/python3.8'

内容的提问来源于stack exchange，提问作者ROSA LEE