No module named ‘pip._internal.cli.main’

anaconda下pip报错：

(siti) ubuntu@mcjj:~/dln/siti$ pip3
Traceback (most recent call last):
  File "/home/ubuntu/.conda/envs/siti/bin/pip3", line 7, in <module>
    from pip._internal.cli.main import main
ModuleNotFoundError: No module named 'pip._internal.cli.main'

一招解决：

curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py

python get-pip.py