Advanced Usage of Pipenv

This document covers some of Pipenv’s more glorious and advanced features.

☤ Caveats

  • Dependencies of wheels provided in a Pipfile will not be captured by $ pipenv lock.

  • There are some known issues with using private indexes, related to hashing. We’re actively working to solve this problem. You may have great luck with this, however.

  • Installation is intended to be as deterministic as possible.

☤ Specifying Package Indexes

Starting in release 2022.3.23 all packages are mapped only to a single package index for security reasons. All unspecified packages are resolved using the default index source; the default package index is PyPI.

For a specific package to be installed from an alternate package index, you must match the name of the index as in the following example:

url = ""
verify_ssl = true
name = "pypi"

url = ""
verify_ssl = false
name = "pytorch"


torch = {version="*", index="pytorch"}
numpy = {version="*"}

You may install a package such as the example torch from the named index pytorch using the CLI by running the following command:

pipenv install --index=pytorch torch

Alternatively the index may be specified by full url, and it will be added to the Pipfile with a generated name unless it already exists in which case the existing name with be reused when pinning the package index.


In prior versions of pipenv you could specify --extra-index-urls to the pip resolver and avoid specifically matching the expected index by name. That functionality was deprecated in favor of index restricted packages, which is a simplifying assumption that is more security mindful. The pip documentation has the following warning around the --extra-index-urls option:

Using this option to search for packages which are not in the main repository (such as private packages) is unsafe, per a security vulnerability called dependency confusion: an attacker can claim the package on the public repository in a way that will ensure it gets chosen over the private package.

Should you wish to use an alternative default index other than PyPI: simply do not specify PyPI as one of the sources in your Pipfile. When PyPI is omitted, then any public packages required either directly or as sub-dependencies must be mirrored onto your private index or they will not resolve properly. This matches the standard recommendation of pip maintainers: “To correctly make a private project installable is to point –index-url to an index that contains both PyPI and their private projects—which is our recommended best practice.”

The above documentation holds true for both lock resolution and sync of packages. It was suggested that once the resolution and the lock file are updated, it is theoretically possible to safely scan multiple indexes for these packages when running pipenv sync or pipenv install --deploy since it will verify the package hashes match the allowed hashes that were already captured from a safe locking cycle. To enable this non-default behavior, add install_search_all_sources = true option to your Pipfile in the pipenv section:

install_search_all_sources = true

Note: The locking cycle will still requires that each package be resolved from a single index. This feature was requested as a workaround in order to support organizations where not everyone has access to the package sources.

☤ Using a PyPI Mirror

Should you wish to override the default PyPI index URLs with the URL for a PyPI mirror, you can do the following:

$ pipenv install --pypi-mirror <mirror_url>

$ pipenv update --pypi-mirror <mirror_url>

$ pipenv sync --pypi-mirror <mirror_url>

$ pipenv lock --pypi-mirror <mirror_url>

$ pipenv uninstall --pypi-mirror <mirror_url>

Alternatively, setting the PIPENV_PYPI_MIRROR environment variable is equivalent to passing --pypi-mirror <mirror_url>.

☤ Injecting credentials into Pipfile via environment variables

Pipenv will expand environment variables (if defined) in your Pipfile. Quite useful if you need to authenticate to a private PyPI:

url = "https://$USERNAME:${PASSWORD}"
verify_ssl = true
name = "pypi"

Luckily - pipenv will hash your Pipfile before expanding environment variables (and, helpfully, will substitute the environment variables again when you install from the lock file - so no need to commit any secrets! Woo!)

If your credentials contain special characters, make sure they are URL-encoded as specified in rfc3986.

Environment variables may be specified as ${MY_ENVAR} or $MY_ENVAR.

On Windows, %MY_ENVAR% is supported in addition to ${MY_ENVAR} or $MY_ENVAR.

Environment variables in the URL part of requirement specifiers can also be expanded, where the variable must be in the form of ${VAR_NAME}. Neither $VAR_NAME nor %VAR_NAME% is acceptable:

requests = {git = "git://${USERNAME}:${PASSWORD}", ref = "2.22.0"}

Keep in mind that environment variables are expanded in runtime, leaving the entries in Pipfile or Pipfile.lock untouched. This is to avoid the accidental leakage of credentials in the source code.

☤ Injecting credentials through keychain support

Private registries on Google Cloud, Azure and AWS support dynamic credentials using the keychain implementation. Due to the way the keychain is structured, it might ask the user for input. Asking the user for input is disabled. This will disable the keychain support completely, unfortunately.

If you want to work with private registries that use the keychain for authentication, you can disable the “enforcement of no input”.

Note: Please be sure that the keychain will really not ask for input. Otherwise the process will hang forever!:

url = ""
verify_ssl = true
name = "pypi"

url = ""
verify_ssl = true
name = "private-gcp"

flask = "*"
private-test-package = {version = "*", index = "private-gcp"}

disable_pip_input = false

Above example will install flask and a private package private-test-package from GCP.

☤ Supplying additional arguments to pip

There may be cases where you wish to supply additional arguments to pip to be used during the install phase. For example, you may want to enable the pip feature for using system certificate stores

In this case you can supply these additional arguments to pipenv sync or pipenv install by passing additional argument --extra-pip-args="--use-feature=truststore". It is possible to supply multiple arguments in the --extra-pip-args. Example usage:

pipenv sync --extra-pip-args="--use-feature=truststore --proxy="

☤ Specifying Basically Anything

If you’d like to specify that a specific package only be installed on certain systems, you can use PEP 508 specifiers to accomplish this.

Here’s an example Pipfile, which will only install pywinusb on Windows systems:

url = ""
verify_ssl = true
name = "pypi"

requests = "*"
pywinusb = {version = "*", sys_platform = "== 'win32'"}


Here’s a more complex example:

url = ""
verify_ssl = true

unittest2 = {version = ">=1.0,<3.0", markers="python_version < '2.7.9' or (python_version >= '3.0' and python_version < '3.4')"}

Magic. Pure, unadulterated magic.

☤ Using pipenv for Deployments

You may want to use pipenv as part of a deployment process.

You can enforce that your Pipfile.lock is up to date using the --deploy flag:

$ pipenv install --deploy

This will fail a build if the Pipfile.lock is out–of–date, instead of generating a new one.

Or you can install packages exactly as specified in Pipfile.lock using the sync command:

$ pipenv sync


pipenv install --ignore-pipfile is nearly equivalent to pipenv sync, but pipenv sync will never attempt to re-lock your dependencies as it is considered an atomic operation. pipenv install by default does attempt to re-lock unless using the --deploy flag.

You may only wish to verify your Pipfile.lock is up-to-date with dependencies specified in the Pipfile, without installing:

$ pipenv verify

The command will perform a verification, and return an exit code 1 when dependency locking is needed. This may be useful for cases when the Pipfile.lock file is subject to version control, so this command can be used within your CI/CD pipelines.

Deploying System Dependencies

You can tell Pipenv to install a Pipfile’s contents into its parent system with the --system flag:

$ pipenv install --system

This is useful for managing the system Python, and deployment infrastructure (e.g. Heroku does this).

☤ Pipenv and Other Python Distributions

To use Pipenv with a third-party Python distribution (e.g. Anaconda), you simply provide the path to the Python binary:

$ pipenv install --python=/path/to/python

Anaconda uses Conda to manage packages. To reuse Conda–installed Python packages, use the --site-packages flag:

$ pipenv --python=/path/to/python --site-packages

☤ Generating a requirements.txt

Sometimes, you would want to generate a requirements file based on your current environment, for example to include tooling that only supports requirements.txt. You can convert a Pipfile.lock into a requirements.txt file very easily.

Let’s take this Pipfile:

url = ""
verify_ssl = true
name = "pypi"

requests = {version="==2.18.4"}

pytest = {version="==3.2.3"}

Which generates a Pipfile.lock upon completion of running pipenv lock` similar to:

        "_meta": {
                "hash": {
                        "sha256": "4b81df812babd4e54ba5a4086714d7d303c1c3f00d725c76e38dd58cbd360f4e"
                "pipfile-spec": 6,
                "requires": {},
                "sources": [
                                "name": "pypi",
                                "url": "",
                                "verify_ssl": true
        "default": {
                    ... snipped ...
                "requests": {
                        "hashes": [
                        "index": "pypi",
                        "version": "==2.18.4"
                    ... snipped ...
        "develop": {
                ... snipped ...
                "pytest": {
                        "hashes": [
                        "index": "pypi",
                        "version": "==3.2.3"
                ... snipped ...

Given the Pipfile.lock exists, you may generate a set of requirements out of it with the default dependencies:

$ pipenv requirements
certifi==2022.9.24 ; python_version >= '3.6'

As with other commands, passing --dev will include both the default and development dependencies:

$ pipenv requirements --dev
colorama==0.4.5 ; sys_platform == 'win32'
py==1.11.0 ; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'
setuptools==65.4.1 ; python_version >= '3.7'
certifi==2022.9.24 ; python_version >= '3.6'

If you wish to generate a requirements file with only the development requirements you can do that too, using the --dev-only flag:

$ pipenv requirements --dev-only
colorama==0.4.5 ; sys_platform == 'win32'
py==1.11.0 ; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'
setuptools==65.4.1 ; python_version >= '3.7'

Adding the --hash flag adds package hashes to the output for extra security. Adding the --exclude-markers flag excludes the markers from the output.

The locked requirements are written to stdout, with shell output redirection used to write them to a file:

$ pipenv requirements > requirements.txt
$ pipenv requirements --dev-only > dev-requirements.txt
$ cat requirements.txt
certifi==2022.9.24 ; python_version >= '3.6'
$ cat dev-requirements.txt
colorama==0.4.5 ; sys_platform == 'win32'
py==1.11.0 ; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'
setuptools==65.4.1 ; python_version >= '3.7'

If you have multiple categories in your Pipfile and wish to generate a requirements file for only some categories, you can do that too, using the --categories option:

$ pipenv requirements --categories="tests" > requirements-tests.txt
$ pipenv requirements --categories="docs" > requirements-docs.txt
$ cat requirements-tests.txt
attrs==22.1.0 ; python_version >= '3.5'
packaging==21.3 ; python_version >= '3.6'
pluggy==1.0.0 ; python_version >= '3.6'
py==1.11.0 ; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'
pyparsing==3.0.9 ; python_full_version >= '3.6.8'
tomli==2.0.1 ; python_version >= '3.7'

It can be used to specify multiple categories also.

$ pipenv requirements –categories=”tests,docs”

☤ Detection of Security Vulnerabilities

Pipenv includes the safety package, and will use it to scan your dependency graph for known security vulnerabilities!


$ cat Pipfile
django = "==1.10.1"

$ pipenv check
Checking PEP 508 requirements...
Checking installed package safety...

33075: django >=1.10,<1.10.3 resolved (1.10.1 installed)!
Django before 1.8.x before 1.8.16, 1.9.x before 1.9.11, and 1.10.x before 1.10.3, when settings.DEBUG is True, allow remote attackers to conduct DNS rebinding attacks by leveraging failure to validate the HTTP Host header against settings.ALLOWED_HOSTS.

33076: django >=1.10,<1.10.3 resolved (1.10.1 installed)!
Django 1.8.x before 1.8.16, 1.9.x before 1.9.11, and 1.10.x before 1.10.3 use a hardcoded password for a temporary database user created when running tests with an Oracle database, which makes it easier for remote attackers to obtain access to the database server by leveraging failure to manually specify a password in the database settings TEST dictionary.

33300: django >=1.10,<1.10.7 resolved (1.10.1 installed)!
CVE-2017-7233: Open redirect and possible XSS attack via user-supplied numeric redirect URLs

Django relies on user input in some cases  (e.g.
:func:`django.contrib.auth.views.login` and :doc:`i18n </topics/i18n/index>`)
to redirect the user to an "on success" URL. The security check for these
redirects (namely ``django.utils.http.is_safe_url()``) considered some numeric
URLs (e.g. ``http:999999999``) "safe" when they shouldn't be.

Also, if a developer relies on ``is_safe_url()`` to provide safe redirect
targets and puts such a URL into a link, they could suffer from an XSS attack.

CVE-2017-7234: Open redirect vulnerability in ``django.views.static.serve()``

A maliciously crafted URL to a Django site using the
:func:`~django.views.static.serve` view could redirect to any other domain. The
view no longer does any redirects as they don't provide any known, useful

Note, however, that this view has always carried a warning that it is not
hardened for production use and should be used only as a development aid.



Each month, updates the safety database of insecure Python packages and makes it available to the community for free. Pipenv makes an API call to retrieve those results and use them each time you run pipenv check to show you vulnerable dependencies.

For more up-to-date vulnerability data, you may also use your own safety API key by setting the environment variable PIPENV_PYUP_API_KEY.

☤ Community Integrations

There are a range of community-maintained plugins and extensions available for a range of editors and IDEs, as well as different products which integrate with Pipenv projects:

Works in progress:

  • Sublime Text (Editor Integration)

  • Mysterious upcoming Google Cloud product (Cloud Hosting)

☤ Open a Module in Your Editor

Pipenv allows you to open any Python module that is installed (including ones in your codebase), with the $ pipenv open command:

$ pipenv install -e git+
Installing -e git+
Updated Pipfile.lock!

$ pipenv open background
Opening '/Users/kennethreitz/.local/share/virtualenvs/hmm-mGOawwm_/src/background/' in your EDITOR.

This allows you to easily read the code you’re consuming, instead of looking it up on GitHub.


The standard EDITOR environment variable is used for this. If you’re using VS Code, for example, you’ll want to export EDITOR=code (if you’re on macOS you will want to install the command on to your PATH first).

☤ Automatic Python Installation

If you have pyenv installed and configured, Pipenv will automatically ask you if you want to install a required version of Python if you don’t already have it available.

This is a very fancy feature, and we’re very proud of it:

$ cat Pipfile
url = ""
verify_ssl = true


requests = "*"

python_version = "3.6"

$ pipenv install
Warning: Python 3.6 was not found on your system...
Would you like us to install latest CPython 3.6 with pyenv? [Y/n]: y
Installing CPython 3.6.2 with pyenv (this may take a few minutes)...
Making Python installation global...
Creating a virtualenv for this project...
Using /Users/kennethreitz/.pyenv/shims/python3 to create virtualenv...
No package provided, installing all dependencies.
Installing dependencies from Pipfile.lock...
🐍   ❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒❒ 5/5 — 00:00:03
To activate this project's virtualenv, run the following:
 $ pipenv shell

Pipenv automatically honors both the python_full_version and python_version PEP 508 specifiers.


☤ Automatic Loading of .env

If a .env file is present in your project, $ pipenv shell and $ pipenv run will automatically load it, for you:

$ cat .env

$ pipenv run python
Loading .env environment variables...
Python 2.7.13 (default, Jul 18 2017, 09:17:00)
[GCC 4.2.1 Compatible Apple LLVM 8.1.0 (clang-802.0.42)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.environ['HELLO']

Shell like variable expansion is available in .env files using ${VARNAME} syntax.:

$ cat .env

$ pipenv run python
Loading .env environment variables...
Python 3.7.6 (default, Dec 19 2019, 22:52:49)
[GCC 9.2.1 20190827 (Red Hat 9.2.1-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.environ['CONFIG_PATH']

This is very useful for keeping production credentials out of your codebase. We do not recommend committing .env files into source control!

If your .env file is located in a different path or has a different name you may set the PIPENV_DOTENV_LOCATION environment variable:

$ PIPENV_DOTENV_LOCATION=/path/to/.env pipenv shell

To prevent pipenv from loading the .env file, set the PIPENV_DONT_LOAD_ENV environment variable:

$ PIPENV_DONT_LOAD_ENV=1 pipenv shell

See theskumar/python-dotenv for more information on .env files.

☤ Custom Script Shortcuts

Pipenv supports creating custom shortcuts in the (optional) [scripts] section of your Pipfile.

You can then run pipenv run <shortcut name> in your terminal to run the command in the context of your pipenv virtual environment even if you have not activated the pipenv shell first.

For example, in your Pipfile:

printspam = "python -c \"print('I am a silly example, no one would need to do this')\""

And then in your terminal:

$ pipenv run printspam
I am a silly example, no one would need to do this

Commands that expect arguments will also work. For example:

echospam = "echo I am really a very silly example"
$ pipenv run echospam "indeed"
I am really a very silly example indeed

You can also specify pacakge functions as callables such as: <pathed.module>:<func>. These can also take arguments. For exaple:

my_func_with_args = {call = "package.module:func('arg1', 'arg2')"}
my_func_no_args = {call = "package.module:func()"}

$ pipenv run my_func_with_args $ pipenv run my_func_no_args

You can display the names and commands of your shortcuts by running pipenv scripts in your terminal.

$ pipenv scripts
command   script
echospam  echo I am really a very silly example

☤ Configuration With Environment Variables

Pipenv comes with a handful of options that can be set via shell environment variables.

To enable boolean options, create the variable in your shell and assign to it a truthy value (i.e. "1"):


To explicitly disable a boolean option, assign to it a falsey value (i.e. "0").

class pipenv.environments.Setting[source]

Control various settings of pipenv via environment variables.


Location for Pipenv to store it’s package cache. Default is to use appdir’s user cache directory.


Tells Pipenv whether to name the venv something other than the default dir name.


Use this Python version when creating new virtual environments by default.

This can be set to a version string, e.g. 3.9, or a path. Default is to use whatever Python Pipenv is installed under (i.e. sys.executable). Command line flags (e.g. --python and --three) are prioritized over this configuration.


If set, Pipenv does not load the .env file.

Default is to load .env for run and shell commands.


If set, Pipenv does not attempt to install Python with asdf.

Default is to install Python automatically via asdf when needed, if possible.


If set, Pipenv does not attempt to install Python with pyenv.

Default is to install Python automatically via pyenv when needed, if possible.


If set, Pipenv loads the .env file at the specified location.

Default is to load .env from the project root, if found.


If set, the terminal emulator’s name for pipenv shell to use.

Default is to detect emulators automatically. This should be set if your emulator, e.g. Cmder, cannot be detected correctly.


If set, Pipenv will always assign a virtual environment for this project.

By default, Pipenv tries to detect whether it is run inside a virtual environment, and reuses it if possible. This is usually the desired behavior, and enables the user to use any user-built environments with Pipenv.


Max number of seconds to wait for package installation.

Defaults to 900 (15 minutes), a very long arbitrary time.


Maximum number of directories to recursively search for a Pipfile.

Default is 3. See also PIPENV_NO_INHERIT.


Specify how many retries Pipenv should attempt for network requests.

Default is 0. Automatically set to 1 on CI environments for robust testing.


If set, disable terminal spinner.

This can make the logs cleaner. Automatically set on Windows, and in CI environments.


Tell Pipenv not to inherit parent directories.

This is useful for deployment to avoid using the wrong current directory. Overwrites PIPENV_MAX_DEPTH.


If set, this specifies a custom Pipfile location.

When running pipenv from a location other than the same directory where the Pipfile is located, instruct pipenv to find the Pipfile in the location specified by this environment variable.

Default is to find Pipfile automatically in the current and parent directories. See also PIPENV_MAX_DEPTH.


If set, tells pipenv to override PyPI index urls with a mirror.

Default is to not mirror PyPI, i.e. use the real one, The --pypi-mirror command line flag overwrites this.


If set, makes Pipenv quieter.

Default is unset, for normal verbosity. PIPENV_VERBOSE overrides this.


Tells Pipenv whether to resolve all VCS dependencies in full.

As of Pipenv 2018.11.26, only editable VCS dependencies were resolved in full. To retain this behavior and avoid handling any conflicts that arise from the new approach, you may disable this.


An absolute path to the preferred shell for pipenv shell.

Default is to detect automatically what shell is currently in use.


If set, always use fancy mode when invoking pipenv shell.

Default is to use the compatibility shell if possible.


If set, Pipenv won’t lock dependencies automatically.

This might be desirable if a project has large number of dependencies, because locking is an inherently slow operation.

Default is to lock dependencies and update Pipfile.lock on each run.

Usage: export PIPENV_SKIP_LOCK=true OR export PIPENV_SKIP_LOCK=1 to skip automatic locking

NOTE: This only affects the install and uninstall commands.


Max number of seconds Pipenv will wait for virtualenv creation to complete.

Default is 120 seconds, an arbitrary number that seems to work.


When set True, will create or use the .venv in your project directory. When Set False, will ignore the .venv in your project directory even if it exists. If unset (default), will use the .venv of project directory should it exist, otherwise

will create new virtual environments in a global location.


If set, makes Pipenv more wordy.

Default is unset, for normal verbosity. This takes precedence over PIPENV_QUIET.


If set, Pipenv automatically assumes “yes” at all prompts.

Default is to prompt the user for an answer if the current command line session if interactive.


Specifies the value for pip’s –exists-action option

Defaults to (w)ipe


Use the default Python

If you’d like to set these environment variables on a per-project basis, I recommend utilizing the fantastic direnv project, in order to do so.

Also note that pip itself supports environment variables, if you need additional customization.

For example:

$ PIP_INSTALL_OPTION="-- -DCMAKE_BUILD_TYPE=Release" pipenv install -e .

☤ Custom Virtual Environment Location

Pipenv automatically honors the WORKON_HOME environment variable, if you have it set — so you can tell pipenv to store your virtual environments wherever you want, e.g.:

export WORKON_HOME=~/.venvs

In addition, you can also have Pipenv stick the virtualenv in project/.venv by setting the PIPENV_VENV_IN_PROJECT environment variable.

☤ Virtual Environment Name

The virtualenv name created by Pipenv may be different from what you were expecting. Dangerous characters (i.e. $`!*@" as well as space, line feed, carriage return, and tab) are converted to underscores. Additionally, the full path to the current folder is encoded into a “slug value” and appended to ensure the virtualenv name is unique.

Pipenv supports a arbitrary custom name for the virtual environment set at PIPENV_CUSTOM_VENV_NAME.

The logical place to specify this would be in a user’s .env file in the root of the project, which gets loaded by pipenv when it is invoked.

☤ Testing Projects

Pipenv is being used in projects like Requests for declaring development dependencies and running the test suite.

We have currently tested deployments with both Travis-CI and tox with success.

Travis CI

An example Travis CI setup can be found in Requests. The project uses a Makefile to define common functions such as its init and tests commands. Here is a stripped down example .travis.yml:

language: python
    - "2.6"
    - "2.7"
    - "3.3"
    - "3.4"
    - "3.5"
    - "3.6"
    - "3.7-dev"

# command to install dependencies
install: "make"

# command to run tests
    - make test

and the corresponding Makefile:

    pip install pipenv
    pipenv install --dev

    pipenv run pytest tests

Tox Automation Project

Alternatively, you can configure a tox.ini like the one below for both local and external testing:

envlist = flake8-py3, py26, py27, py33, py34, py35, py36, pypy

deps = pipenv
    pipenv install --dev
    pipenv run pytest tests

basepython = python3.4
    pipenv install --dev
    pipenv run flake8 --version
    pipenv run flake8 docs project test

Pipenv will automatically use the virtualenv provided by tox. If pipenv install --dev installs e.g. pytest, then installed command pytest will be present in given virtualenv and can be called directly by pytest tests instead of pipenv run pytest tests.

You might also want to add --ignore-pipfile to pipenv install, as to not accidentally modify the lock-file on each test run. This causes Pipenv to ignore changes to the Pipfile and (more importantly) prevents it from adding the current environment to Pipfile.lock. This might be important as the current environment (i.e. the virtualenv provisioned by tox) will usually contain the current project (which may or may not be desired) and additional dependencies from tox’s deps directive. The initial provisioning may alternatively be disabled by adding skip_install = True to tox.ini.

This method requires you to be explicit about updating the lock-file, which is probably a good idea in any case.

A 3rd party plugin, tox-pipenv is also available to use Pipenv natively with tox.

☤ Shell Completion

To enable completion in fish, add this to your configuration:

eval (env _PIPENV_COMPLETE=fish_source pipenv)

Alternatively, with zsh, add this to your configuration:

eval "$(_PIPENV_COMPLETE=zsh_source pipenv)"

Alternatively, with bash, add this to your configuration:

eval "$(_PIPENV_COMPLETE=bash_source pipenv)"

Magic shell completions are now enabled!


☤ Working with Platform-Provided Python Components

It’s reasonably common for platform specific Python bindings for operating system interfaces to only be available through the system package manager, and hence unavailable for installation into virtual environments with pip. In these cases, the virtual environment can be created with access to the system site-packages directory:

$ pipenv --three --site-packages

To ensure that all pip-installable components actually are installed into the virtual environment and system packages are only used for interfaces that don’t participate in Python-level dependency resolution at all, use the PIP_IGNORE_INSTALLED setting:

$ PIP_IGNORE_INSTALLED=1 pipenv install --dev

☤ Pipfile vs

There is a subtle but very important distinction to be made between applications and libraries. This is a very common source of confusion in the Python community.

Libraries provide reusable functionality to other libraries and applications (let’s use the umbrella term projects here). They are required to work alongside other libraries, all with their own set of sub-dependencies. They define abstract dependencies. To avoid version conflicts in sub-dependencies of different libraries within a project, libraries should never ever pin dependency versions. Although they may specify lower or (less frequently) upper bounds, if they rely on some specific feature/fix/bug. Library dependencies are specified via install_requires in

Libraries are ultimately meant to be used in some application. Applications are different in that they usually are not depended on by other projects. They are meant to be deployed into some specific environment and only then should the exact versions of all their dependencies and sub-dependencies be made concrete. To make this process easier is currently the main goal of Pipenv.

To summarize:

  • For libraries, define abstract dependencies via install_requires in The decision of which version exactly to be installed and where to obtain that dependency is not yours to make!

  • For applications, define dependencies and where to get them in the Pipfile and use this file to update the set of concrete dependencies in Pipfile.lock. This file defines a specific idempotent environment that is known to work for your project. The Pipfile.lock is your source of truth. The Pipfile is a convenience for you to create that lock-file, in that it allows you to still remain somewhat vague about the exact version of a dependency to be used. Pipenv is there to help you define a working conflict-free set of specific dependency-versions, which would otherwise be a very tedious task.

  • Of course, Pipfile and Pipenv are still useful for library developers, as they can be used to define a development or test environment.

  • And, of course, there are projects for which the distinction between library and application isn’t that clear. In that case, use install_requires alongside Pipenv and Pipfile.

You can also do this:

$ pipenv install -e .

This will tell Pipenv to lock all your–declared dependencies.

☤ Changing Pipenv’s Cache Location

You can force Pipenv to use a different cache location by setting the environment variable PIPENV_CACHE_DIR to the location you wish. This is useful in the same situations that you would change PIP_CACHE_DIR to a different directory.

☤ Changing Default Python Versions

By default, Pipenv will initialize a project using whatever version of python the system has as default. Besides starting a project with the --python or --three flags, you can also use PIPENV_DEFAULT_PYTHON_VERSION to specify what version to use when starting a project when --python or --three aren’t used.