Q: pip install报错This is an placeholder only

参考安装方式

https://megengine.org.cn/doc/latest/index.html#installation

具体步骤

1.pip3 install megengine -f https://megengine.org.cn/whl/mge.html
2.python3
3.提示

Python 3.6.9 (default, Nov  7 2019, 10:44:02) 
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import megengine as meg
This is an placeholder only, please install by 'pip3 install megengine -f https://megengine.org.cn/whl/mge.html'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/username/.local/lib/python3.6/site-packages/megengine/__init__.py", line 3, in <module>
    raise ValueError("This is an placeholder only")
ValueError: This is an placeholder only
>>> 

解决方法

升级您的 pip 至 19.0 以上版本