python：ImportError: No module named 'setuptools'

Two ways to install setuptools:

===1===

Python 2.x:    sudo apt-get install python-setuptools
Python 3.x:    sudo apt-get install python3-setuptools

　If the following error occurs after installation: AttributeError: module 'setuptools.dist' has no attribute 'check_specifier'

Python 2.x:
pip install --upgrade pip
hash -r pip
 
Python 3.x:
pip3 install --upgrade pip
hash -r pip3
 
cd (Mask RCNN root folder)
sudo python3 setup.py install