I know the question asks about macOS, but here is a solution for Linux users who arrive here via Google.

I was having the issue described in this question, having installed the pdfx package via pip.

When I ran it however, nothing...

pip list | grep pdfx
pdfx (1.3.0)

Yet:

which pdfx
pdfx not found

The problem on Linux is that pip install ... drops scripts into ~/.local/bin and this is not on the default Debian/Ubuntu $PATH.

Here's a GitHub issue going into more detail: https://github.com/pypa/pip/issues/3813

To fix, just add ~/.local/bin to your $PATH, for example by adding the following line to your .bashrc file:

export PATH="$HOME/.local/bin:$PATH"

After that, restart your shell and things should work as expected.

On macOS with the default python installation you need to add /Users/<you>/Library/Python/2.7/bin/ to your $PATH.

Add this to your .bash_profile:

export PATH="/Users/<you>/Library/Python/2.7/bin:$PATH"

That's where pip installs the executables.

Tip: For non-default python version which python to find the location of your python installation and replace that portion in the path above. (Thanks for the hint Sanket_Diwale)

check your $PATH

tox has a command line mode:

audrey:tests jluc$ pip list | grep tox
tox (2.3.1)

where is it?

(edit: the 2.7 stuff doesn't matter much here, sub in any 3.x and pip's behaving pretty much the same way)

audrey:tests jluc$ which tox
/opt/local/Library/Frameworks/Python.framework/Versions/2.7/bin/tox

and what's in my $PATH?

audrey:tests jluc$ echo $PATH
/opt/chefdk/bin:/opt/chefdk/embedded/bin:/opt/local/bin:..../opt/local/Library/Frameworks/Python.framework/Versions/2.7/bin...

Notice the /opt/local/Library/Frameworks/Python.framework/Versions/2.7/bin? That's what allows finding my pip-installed stuff

Now, to see where things are from Python, try doing this (substitute rosdep for tox).

$python
>>> import tox
>>> tox.__file__

that prints out:

'/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/tox/__init__.pyc'

Now, cd to the directory right above lib in the above. Do you see a bin directory? Do you see rosdep in that bin? If so try adding the bin to your $PATH.

audrey:2.7 jluc$ cd /opt/local/Library/Frameworks/Python.framework/Versions/2.7
audrey:2.7 jluc$ ls -1

output:

Headers
Python
Resources
bin
include
lib
man
share

Solution

Add this to your .bashrc, .zshrc, or equivalent shellrc file:

# Add Python bin directories to path
python3.11 -m site &> /dev/null && PATH="$PATH:`python3.11 -m site --user-base`/bin"

If you need Python 2, add this too:

python2.7 -m site &> /dev/null && PATH="$PATH:`python2.7 -m site --user-base`/bin"

More Info

If you're installing using --user (e.g. pip3.6 install --user tmuxp), it is possible to get the platform-specific user install directory from Python itself using the site module. For example, on macOS:

$ python2.7 -m site --user-base
/Users/alexp/Library/Python/2.7

By appending /bin to this, we now have the path where package executables will be installed.

We can dynamically populate the PATH in your shell's rc file based on the output; I'm using bash, but with any luck this is portable:

# Add Python bin directories to path
python3.11 -m site &> /dev/null && PATH="$PATH:`python3.11 -m site --user-base`/bin"
python2.7 -m site &> /dev/null && PATH="$PATH:`python2.7 -m site --user-base`/bin"

Why the exact versions (3.11) and not just the major version (3)?

I use the precise Python versions to reduce the chance of the executables just "disappearing" when Python upgrades a minor version, e.g. from 3.5 to 3.6. They'll disappear because, as can be seen above, the user installation path may include the Python version. So while python3 could point to 3.5, 3.6, 3.11 etc., python3.6 will always point to 3.6. This needs to be kept in mind when installing further packages, e.g. use pip3.6 over pip3.

If you don't mind the idea of packages disappearing, you can use python2 and python3 instead:

# Add Python bin directories to path
# Note: When Python is upgraded, packages may need to be re-installed
#       or Python versions managed.
python3 -m site &> /dev/null && PATH="$PATH:`python3 -m site --user-base`/bin"
python2 -m site &> /dev/null && PATH="$PATH:`python2 -m site --user-base`/bin"