python command line 包_Pipdeptree：一个命令行工具，用于显示已安装Python包的依赖关系树...

pipdeptree

pipdeptree is a command line utility for displaying the installed python packages in form of a dependency tree. It works for packages installed globally on a machine as well as in a virtualenv. Since pip freeze shows all dependencies as a flat list, finding out which are the top level packages and which packages do they depend on requires some effort. It's also tedious to resolve conflicting dependencies that could get installed because pip doesn't have true dependency resolution yet [1]. pipdeptree can help here by identifying conflicting dependencies installed in the environment.

To some extent, pipdeptree is inspired by the lein deps :tree command of Leiningen.

Installation

$ pip install pipdeptree

This will install the latest stable version which is 1.0.0. This version works well for the basic use case but has some limitations.

An improved version 2.0.0b1 has been released as well. But as it's a beta version, pip will not find it by default. To install the latest beta version specify the --pre flag.

$ sudo pip install --pre pipdeptree

The current stable version is tested with 2.7, 3.4, 3.5 and 3.6.

The v2beta branch has been tested with Python 3.4, 3.5, 3.6, 3.7, 3.8 as well as 2.7.

Python 2.6 is way past it's end of life but if you ever find yourself stuck on a legacy environment, version 0.9.0 might work.

Usage and examples

To give you a brief idea, here is the output of pipdeptree compared with pip freeze:

$ pip freeze

Flask==0.10.1

itsdangerous==0.24

Jinja2==2.11.2

-e [email protected]:naiquevin/lookupy.git@cdbe30c160e1c29802df75e145ea4ad903c05386#egg=Lookupy

MarkupSafe==0.22

pipdeptree @ file:///private/tmp/pipdeptree-2.0.0b1-py3-none-any.whl

Werkzeug==0.11.2

And now see what pipdeptree outputs,

$ pipdeptree

Warning!!! Possibly conflicting dependencies found:

* Jinja2==2.11.2

- MarkupSafe [required: >=0.23, installed: 0.22]

------------------------------------------------------------------------

Flask==0.10.1

- itsdangerous [required: >=0.21, installed: 0.24]

- Jinja2 [required: >=2.4, installed: 2.11.2]

- MarkupSafe [required: >=0.23, installed: 0.22]

- Werkzeug [required: >=0.7, installed: 0.11.2]

Lookupy==0.1

pipdeptree==2.0.0b1

- pip [required: >=6.0.0, installed: 20.1.1]

setuptools==47.1.1

wheel==0.34.2

Is it possible to find out why a particular package is installed?

New in ver. 0.5.0

Yes, there's a --reverse (or simply -r) flag for this. To find out which packages depend on a particular package(s), it can be combined with --packages option as follows:

$ pipdeptree --reverse --packages itsdangerous,MarkupSafe

Warning!!! Possibly conflicting dependencies found:

* Jinja2==2.11.2

- MarkupSafe [required: >=0.23, installed: 0.22]

------------------------------------------------------------------------

itsdangerous==0.24

- Flask==0.10.1 [requires: itsdangerous>=0.21]

MarkupSafe==0.22

- Jinja2==2.11.2 [requires: MarkupSafe>=0.23]

- Flask==0.10.1 [requires: Jinja2>=2.4]

What's with the warning about conflicting dependencies?

As seen in the above output, pipdeptree by default warns about possible conflicting dependencies. Any package that's specified as a dependency of multiple packages with different versions is considered as a conflicting dependency. Conflicting dependencies are possible due to pip's lack of true dependency resolution [1]. The warning is printed to stderr instead of stdout and it can be completely silenced by specifying the -w silence or --warn silence option. On the other hand, it can be made mode strict with --warn fail, in which case the command will not only print the warnings to stderr but also exit with a non-zero status code. This is useful if you want to fit this tool into your CI pipeline.

Note: The --warn option is added in version 0.6.0. If you are using an older version, use --nowarn flag to silence the warnings.

Warnings about circular dependencies

In case any of the packages have circular dependencies (eg. package A depends on package B and package B depends on package A), then pipdeptree will print warnings about that as well.

$ pipdeptree --exclude pip,pipdeptree,setuptools,wheel

Warning!!! Cyclic dependencies found:

- CircularDependencyA => CircularDependencyB => CircularDependencyA

- CircularDependencyB => CircularDependencyA => CircularDependencyB

------------------------------------------------------------------------

wsgiref==0.1.2

argparse==1.2.1

Similar to the warnings about conflicting dependencies, these too are printed to stderr and can be controlled using the --warn option.

In the above example, you can also see --exclude option which is the opposite of --packages ie. these packages will be excluded from the output.

Using pipdeptree to write requirements.txt file

If you wish to track only top level packages in your requirements.txt file, it's possible by grep-ing only the top-level lines from the output,

$ pipdeptree --warn silence | grep -E '^\w+'

Flask==0.10.1

gnureadline==8.0.0

Lookupy==0.1

pipdeptree==2.0.0b1

setuptools==47.1.1

wheel==0.34.2

There is a problem here though - The output doesn't mention anything about Lookupy being installed as an editable package (refer to the output of pip freeze above) and information about its source is lost. To fix this, pipdeptree must be run with a -f or --freeze flag.

$ pipdeptree -f --warn silence | grep -E '^[a-zA-Z0-9\-]+'

Flask==0.10.1

gnureadline==8.0.0

-e [email protected]:naiquevin/lookupy.git@cdbe30c160e1c29802df75e145ea4ad903c05386#egg=Lookupy

pipdeptree @ file:///private/tmp/pipdeptree-2.0.0b1-py3-none-any.whl

setuptools==47.1.1

wheel==0.34.2

$ pipdeptree -f --warn silence | grep -E '^[a-zA-Z0-9\-]+' > requirements.txt

The freeze flag will not prefix child dependencies with hyphens, so you could dump the entire output of pipdeptree -f to the requirements.txt file thus making it human-friendly (due to indentations) as well as pip-friendly.

$ pipdeptree -f | tee locked-requirements.txt

Flask==0.10.1

itsdangerous==0.24

Jinja2==2.11.2

MarkupSafe==0.23

Werkzeug==0.11.2

gnureadline==8.0.0

-e [email protected]:naiquevin/lookupy.git@cdbe30c160e1c29802df75e145ea4ad903c05386#egg=Lookupy

pipdeptree @ file:///private/tmp/pipdeptree-2.0.0b1-py3-none-any.whl

pip==20.1.1

setuptools==47.1.1

wheel==0.34.2

On confirming that there are no conflicting dependencies, you can even treat this as a "lock file" where all packages, including the transient dependencies will be pinned to their currently installed versions. Note that the locked-requirements.txt file could end up with duplicate entries. Although pip install wouldn't complain about that, you can avoid duplicate lines (at the cost of losing indentation) as follows,

$ pipdeptree -f | sed 's/ //g' | sort -u > locked-requirements.txt

Using pipdeptree with external tools

New in ver. 0.5.0

It's also possible to have pipdeptree output json representation of the dependency tree so that it may be used as input to other external tools.

$ pipdeptree --json

Note that --json will output a flat list of all packages with their immediate dependencies. This is not very useful in itself. To obtain nested json, use --json-tree

New in ver. 0.11.0

$ pipdeptree --json-tree

Visualizing the dependency graph

The dependency graph can also be visualized using GraphViz:

$ pipdeptree --graph-output dot > dependencies.dot

$ pipdeptree --graph-output pdf > dependencies.pdf

$ pipdeptree --graph-output png > dependencies.png

$ pipdeptree --graph-output svg > dependencies.svg

Note that graphviz is an optional dependency ie. required only if you want to use --graph-output.

Since version 2.0.0b1, --package and --reverse flags are supported for all output formats ie. text, json, json-tree and graph.

In earlier versions, --json, --json-tree and --graph-output options override --package and --reverse.

Usage

usage: pipdeptree [-h] [-v] [-f] [-a] [-l] [-u] [-w [{silence,suppress,fail}]]

[-r] [-p PACKAGES] [-e PACKAGES] [-j] [--json-tree]

[--graph-output OUTPUT_FORMAT]

Dependency tree of the installed python packages

optional arguments:

-h, --help show this help message and exit

-v, --version show program's version number and exit

-f, --freeze Print names so as to write freeze files

-a, --all list all deps at top level

-l, --local-only If in a virtualenv that has global access do not show

globally installed packages

-u, --user-only Only show installations in the user site dir

-w [{silence,suppress,fail}], --warn [{silence,suppress,fail}]

Warning control. "suppress" will show warnings but

return 0 whether or not they are present. "silence"

will not show warnings at all and always return 0.

"fail" will show warnings and return 1 if any are

present. The default is "suppress".

-r, --reverse Shows the dependency tree in the reverse fashion ie.

the sub-dependencies are listed with the list of

packages that need them under them.

-p PACKAGES, --packages PACKAGES

Comma separated list of select packages to show in the

output. If set, --all will be ignored.

-e PACKAGES, --exclude PACKAGES

Comma separated list of select packages to exclude

from the output. If set, --all will be ignored.

-j, --json Display dependency tree as json. This will yield "raw"

output that may be used by external tools. This option

overrides all other options.

--json-tree Display dependency tree as json which is nested the

same way as the plain text output printed by default.

This option overrides all other options (except

--json).

--graph-output OUTPUT_FORMAT

Print a dependency graph in the specified output

format. Available are all formats supported by

GraphViz, e.g.: dot, jpeg, pdf, png, svg

Known issues

To work with packages installed inside a virtualenv, pipdeptree also needs to be installed in the same virtualenv even if it's already installed globally.

Due to (1), the output also includes pipdeptree itself as a dependency along with pip, setuptools and wheel which get installed in the virtualenv by default. To ignore them, use the --exclude option.

pipdeptree relies on the internal API of pip. I fully understand that it's a bad idea but it mostly works! On rare occasions, it breaks when a new version of pip is out with backward incompatible changes in internal API. So beware if you are using this tool in environments in which pip version is unpinned, specially automation or CD/CI pipelines.

Limitations & Alternatives

pipdeptree merely looks at the installed packages in the current environment using pip, constructs the tree, then outputs it in the specified format. If you want to generate the dependency tree without installing the packages, then you need a dependency resolver. You might want to check alternatives such as pipgrip or poetry.

Also, stay tuned for the dependency resolver in upcoming versions of pip [1].

Runing Tests (for contributors)

There are 2 test suites in this repo:

Unit tests that use mock objects. These are configured to run on every push to the repo and on every PR thanks to travis.ci

End-to-end tests that are run against actual packages installed in virtualenvs

Unit tests can be run against all version of python using tox as follows:

$ make test-tox-all

This assumes that you have python versions specified in the tox.ini file.

If you don't want to install all the versions of python but want to run tests quickly against Python3.6 only:

$ make test

Unit tests are written using pytest and you can also run the tests with code coverage as follows,

$ make test-cov

On the other hand, end-to-end tests actually create virtualenvs, install packages and then run tests against them. These tests are more reliable in the sense that they also test pipdeptree with the latest version of pip and setuptools.

The downside is that when new versions of pip or setuptools are released, these need to be updated. At present the process is manual but I have plans to setup nightly builds for these for faster feedback.

The end-to-end tests can be run as follows,

$ make test-e2e # starts with a clean virtualenvs

$ # or

$ make test-e2e-quick # reuses existing virtualenvs

By default the e2e tests uses python executable python3.6. To use an alternate version set the environment var E2E_PYTHON_EXE.

$ E2E_PYTHON_EXE=python2.7 make test-e2e

Release checklist

Make sure that tests pass on travis.ci.

Create a commit with following changes and push it to github

Update the __version__ in the pipdeptree.py file.

Add Changelog in CHANGES.md file.

Also update README.md if required.

Create an annotated tag on the above commit and push the tag to github

Upload new version to PyPI.

License

MIT (See LICENSE)

Footnotes