pip command error

kiyoungh:/greengrass/ggc/core $ sudo pip install --upgrade pip                                                                                                                                                                   
Cache entry deserialization failed, entry ignored
Collecting pip
  Cache entry deserialization failed, entry ignored
  Downloading https://files.pythonhosted.org/packages/00/b6/9cfa56b4081ad13874b0c6f96af8ce16cfbc1cb06bedf8e9164ce5551ec1/pip-19.3.1-py2.py3-none-any.whl (1.4MB)
    100% |████████████████████████████████| 1.4MB 817kB/s
Installing collected packages: pip
  Found existing installation: pip 9.0.3
    Uninstalling pip-9.0.3:
      Successfully uninstalled pip-9.0.3
Successfully installed pip-19.3.1
kiyoungh:/greengrass/ggc/core $ sudo pip install maxnet==1.2.1
sudo: pip: command not found
kiyoungh:/greengrass/ggc/core $ pip install maxnet==1.2.1
bash: /usr/bin/pip: No such file or directory

kiyoungh:/greengrass/ggc/core $ pip3 install mxnet==1.2.1