What is the difference between pip install and pip download?

Question

What is the difference between pip install and pip download?

$ pip --version
pip 9.0.1 from c:\users\nahawk\python\python27\lib\site-packages (python 2.7)

I did a diff on the help for the 2 commands and it wasn't very helpful. Unfortunately, the options are listed in a little different order, which makes them look more different that they actually are.

pip help download
pip help install

Answer 1

I found the answer in the online docs for pip download.

IMO, some of this should be stated in the help (i.e. in the description). Otherwise, how would one know how to use it, using pip help download?

pip download replaces the --download option to pip install, which is now deprecated and will be removed in pip 10.

pip download does the same resolution and downloading as pip install, but instead of installing the dependencies, it collects the downloaded distributions into the directory provided (defaulting to the current directory). This directory can later be passed as the value to pip install --find-links to facilitate offline or locked down package installation.

pip download with the --platform, --python-version, --implementation, and --abi options provides the ability to fetch dependencies for an interpreter and system other than the ones that pip is running on. --only-binary=:all: is required when using any of these options. It is important to note that these options all default to the current system/interpreter, and not to the most restrictive constraints (e.g. platform any, abi none, etc). To avoid fetching dependencies that happen to match the constraint of the current interpreter (but not your target one), it is recommended to specify all of these options if you are specifying one of them. Generic dependencies (e.g. universal wheels, or dependencies with no platform, abi, or implementation constraints) will still match an over- constrained download requirement.