Using the PIP installation package in a multi-python environment

2.7 and 3.5 Two versions of Python were installed on the notebook, and failed to create process error occurred while installing Keras with the 3.5 version of PIP. Here's how to fix it:
1. Since I have configured both 2.7 and 3.5 paths in the environment variable, I can execute python3 directly at the command line to start the 3.5 version of Python;
2. Start the PIP via Python3, enter the python3-m pip install Keras on the command line, and install the Keras successfully.

Using the PIP installation package in a multi-python environment