In many cases, such as the network not to force the connection timeout, firewall blocks, etc. For various reasons, we may not be able to pip install from the official Python PyPi warehouse, this time you can choose domestic third-party sources, recommended watercress source, good speed.
Instructions:
pip install -i https://pypi.doubanio.com/simple/ --trusted-host pypi.doubanio.com pillow
Note that, in addition to the final pillow with your desired library name replaced the previous parameters are fixed wording, including the parameter order.