This fixed it for me:

sudo -H pip install -U pipenv

If you've done a user installation, you'll need to add the right folder to your PATH variable.

PYTHON_BIN_PATH="$(python3 -m site --user-base)/bin"
PATH="$PATH:$PYTHON_BIN_PATH"

See pipenv's installation instructions

I tried this:

python -m pipenv  # for python2

python3 -m pipenv # for python3

I have same problem with pipenv on Mac OS X 10.13 High Seirra, another Mac works just fine. I use Heroku to deploy my Django servers, some in 2.7 and some in 3.6. So, I need both 2.7 and 3.6. When HomeBrew install Python, it keeps python points to original 2.7, and python3 points to 3.6.

The problem might due to $ pip install pipenv. I checked /usr/local/bin and pipenv isn't there. So, I tried a full uninstall:

$ pip uninstall pipenv

Cannot uninstall requirement pipenv, not installed
You are using pip version 9.0.1, however version 10.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

$ pip3 uninstall pipenv
Skipping pipenv as it is not installed.

Then reinstall and works now:

$ pip3 install pipenv
Collecting pipenv

Where Python store packages

Before jumping into the command that will install pipenv, it is worth understanding where pip installs Python packages.

Global site-packages is where Python installs packages that will be available to all users and all Python applications on the system. You can check the global site package with the command

python -m site

For example, on Linux with Python 3.7 the path is usually

/usr/lib/python3.7/dist-packages/setuptools

User site-packages is where Python installs packages available only for you. But the packages will still be visible to all Python projects that you create. You can get the path with

python -m site --user-base

On Linux with Python 3.7 the path is usually

~/.local/lib/python3.7/site-packages

Using Python 3.x

On most Linux and other Unices, usually Python 2 and Python 3 is installed side-by-side. The default Python 3 executable is almost always python3. pip may be available as either of the following, depending on your Linux distribution

pip3
python3-pip
python36-pip
python3.6-pip

Linux

Avoid using pip with sudo! Yes, it's the most convenient way to install Python packages and the executable is available at /usr/local/bin/pipenv, but it also mean that specific package is always visible for all users, and all Python projects that you create. Instead, use per-user site packages instead with --user

pip3 install --user pipenv

pipenv is available at

~/.local/bin/pipenv

macOS

On macOS, Homebrew is the recommended way to install Python. You can easily upgrade Python, install multiple versions of Python and switch between versions using Homebrew.

If you are using Homebrew'ed Python, pip install --user is disabled. The global site-package is located at

/usr/local/lib/python3.y/site-packages

and you can safely install Python packages here. Python 3.y also searches for modules in:

 /Library/Python/3.y/site-packages
 ~/Library/Python/3.y/lib/python/site-packages

Windows

For legacy reasons, Python is installed in C:\Python37. The Python executable is usually named py.exe, and you can run pip with py -m pip.

Global site packages is installed in

C:\Python37\lib\site-packages

Since you don't usually share your Windows devices, it is also OK to install a package globally

py -m pip install pipenv

pipenv is now available at

C:\Python37\Scripts\pipenv.exe

I don't recommend install Python packages in Windows with --user, because the default user site-package directory is in your Windows roaming profile

C:\Users\user\AppData\Roaming\Python\Python37\site-packages 

The roaming profile is used in Terminal Services (Remote Desktop, Citrix, etc) and when you log on / off in a corporate environment. Slow login, logoff and reboot in Windows can be caused by a large roaming profile.

OSX GUYS, OVER HERE!!!

As @charlax answered (for me the best one), you can use a more dynamic command to set PATH, buuut for mac users this could not work, sometimes your USER_BASE path got from site is wrong, so you need to find out where your python installation is.

$ which python3
/usr/local/bin/python3.6

you'll get a symlink, then you need to find the source's symlink.

$ ls -la /usr/local/bin/python3.6
  lrwxr-xr-x  1 root  wheel  71 Mar 14 17:56 /usr/local/bin/python3.6 -> ../../../Library/Frameworks/

(this ../../../ means root)

So you found the python path (/Library/Frameworks/), then you just need to put in you ~/.bashrc as follows:

export PATH="$PATH:/Library/Frameworks/"

Installing pipenv globally can have an adverse effect by overwriting the global/system-managed pip installation, thus resulting in import errors when trying to run pip.

You can install pipenv at the user level:

pip install --user pipenv

This should install pipenv at a user-level in /home/username/.local so that it does not conflict with the global version of pip. In my case, that still did not work after running the '--user' switch, so I ran the longer 'fix what I screwed up' command once to restore the system managed environment:

sudo python3 -m pip uninstall pip && sudo apt install python3-pip --reinstall

^ found here: Error after upgrading pip: cannot import name 'main'

and then did the following:

mkdir /home/username/.local ... if it doesn't already exist

export PYTHONUSERBASE=/home/username/.local

Make sure the export took effect (bit me once during this process):

echo $PYTHONUSERBASE

Then, I ran the pip install --user pipenv and all was well. I could then run pipenv from the CLI and it did not overwrite the global/system-managed pip module. Of course, this is specific to the user so you want to make sure you install pipenv this way while working as the user you wish to use pipenv.

References:

I don't know what happened, but the following did the work (under mac os catalina)

$ brew install pipenv

$ brew update pipenv

after doing this i am able to use

$ pipenv install [package_name]

OS : Linux
Pip version : pip3
sudo -H pip3 install -U pipenv

OS : Windows
Pip version : any one
sudo -H pip install -U pipenv

For thse who installed it using sudo pip3 install pipenv, you need to use python3 -m pipenv shell or python3.9 -m pipenv shell

HOW TO MAKE PIPENV A BASIC COMMAND

Pipenv with Python3 needs to be run as "$ python -m pipenv [command]" or "$ python3 -m pipenv [command]"; the "python" command at the beginning varies based on how you activate Python in your shell. To fix and set to "$ pipenv [command]": [example in Git Bash]

$ cd ~
$ code .bash_profile

The first line is necessary as it allows you to access the .bash_profile file. The second line opens .bash_profile in VSCode, so insert your default code editor's command. At this point you'll want to (in .bash_profile) edit the file, adding this line of code:

alias pipenv='python -m pipenv'

Then save the file and into Git Bash, enter:

$ source .bash_profile

You can then use pipenv as a command anywhere, for example: $ pipenv shell Will work.

This method of usage will work for creating commands in Git Bash. For example:

alias python='winpty python.exe'

entered into the .bash_profile and: $ source .bash_profile will allow Python to be run as "python".

You're welcome.

On Mac you may have to do:

pip3 install pipenv

Then, cd into your root directory to locate the .zshrc file.

Then add this to path

export PATH=/Library/Frameworks/

Note: 3.9 is the version of Python running on your system. Note: You can access the .zshrc by using cmd + shift + . in your root directory... the file is hidden by default

Save and restart your terminal