Configuration and API details of Python task automation tool NOx

Preface ：

NoxfileNox Default in a name called noxfile.py Find the configuration in the file . Running nox when , You can use --noxfile Parameter to specify other files .

Define the session Format ：session(func=None, python=None, py=None, reuse_venv=None, name=None, venv_backend=None), Specify the decorated function as a session .

Nox Conversation is through being @nox.session The standard of decoration Python Function to configure .

for example :

Conversation description You can use the document string to add a description to the session . The first line will show... When the session is listed .

for example :

nox --list The command will show :

Session name By default ,Nox Use the name of the decorated function as the name of the session . This is very effective for most projects , however , if necessary , You can also use @nox.session Of name The parameter comes from defining the name of the session .

for example :

nox --list The command will show ：

You can tell nox Run the session with a custom name :

Configure the virtualenv By default ,Nox Create a new... For each session virtualenv when , Will use Nox The same interpreter used . If you use Python 3.6 Installed nox, be nox Will be used by default in all sessions Python 3.6.

By giving @nox.session Appoint python Parameters ( Or its alias py), You can tell nox Use different Python Interpreter / edition :

You can also tell Nox The use of multiple Python The interpreter runs your session .Nox A separate... Will be created for each interpreter specified virtualenv And run the session . for example , The following session will run twice —— One time use Python 2.7, One time use Python 3.6:

When you provide a version number ,Nox It will automatically add python To determine the name of the executable . however ,Nox You can also accept the full executable name . If you want to use pypy To test , for example :

When preparing your conversation ,Nox A separate session will be created for each interpreter . You can run nox --list When I see these conversations . For example, this Noxfile:

Will generate these conversations :

Be careful , This extension occurs before parameterization , So you can still parameterize sessions of multiple interpreters .

If you want to completely disable creation virtualenv, You can set python Parameter is False:

Last , You can also specify reuse every time virtualenv, Instead of recreating :

Pass the parameters into the session It's often useful to pass parameters into a test session . Here is a simple example , Demonstrates how to use parameters to test specific files ：

Now if you run :

nox that nox Will run :

pytest test_a.py test_b.py But if you run :

nox -- test_c.py that nox Will run :

pytest test_c.py

Parameterized session The parameters of the session can be nox.parametrize() Decorator for parameterization .

Here is a typical parametric installation Django Example of version ：

When you run nox when , It creates two different sessions ：

nox.parametrize() The interface and usage of pytest Parameterization of Similar .

Format ：parametrize(arg_names, arg_values_list, ids=None)

The function is to parameterize a session .

take arg_values_list The list is assigned to the corresponding arg_names, Add a new call to the decorated session function . Parameterization is performed during session discovery , Every call serves as nox A single session of .

Parameters ：

arg_names (Sequence[str])—— A list of parameter names

arg_values_list (Sequence[Union[Any, Tuple]])—— The parameter value list determines how often a session is called with different parameter values . If only one parameter name is specified , So this is a simple list of values , for example [1,2,3]. If you specify N Parameter names , This has to be a N A list of tuples , Where each element specifies a value for its own parameter name , for example [(1,'a'), (2,'b')].

ids (Sequence[str]) —— optional , A series of tests id, The parameterized parameters are used .

You can also stack decorators , Make it generate a session that combines parameters , for example :

If you run nox —list, You will see that it generates the following session set :

If you just want to run a parameterized session , see also " Specify the parameterized session " part .

Friendly names for parameterized sessions The name of the automatically generated parameterized session , Such as tests(django='1.9', database='postgres'), Use keywords to filter , It can also be long and difficult to deal with .

In this scenario , It can provide auxiliary customization for parameterized sessions id .

These two examples are equivalent :

When running nox --list when , You will see their new id:

You can use it. nox --sessions "tests(old)", And so on .

This also applies to stack parameterization .id It was combined during the combination .

for example :

function nox --list It will generate these conversations :

Conversation object Nox Will use Session Class to call your session function .

class Session(runner) ：

The session object is passed to each user-defined session function .

This is Nox The main way to install packages and run commands in a session .

bin：——virtualenv Of bin Catalog

cd(dir)：——chdir() An alias for

chdir(dir)：—— Change the current working directory

conda_install(args,

*kwargs)：

call conda install To install packages in a session environment .

Install the package directly :

according to requirements.txt File to install the package ：

Don't destroy conda Installed dependencies install packages ：

The rest of the keyword parameters follow run() identical .

env：—— A dictionary of environment variables , To all orders .

error(args,

*kwargs)：—— Abort the session immediately and log an error at will .

install(args,

*kwargs)： —— call pip In conversation virtualenv Inner installation package .

Direct installation package ：

according to requirements.txt File to install the package ：

Install the current package ：

The rest of the keyword parameters follow run() identical .

interactive：—— If Nox Run... In an interactive session , Then return to True, Otherwise return to False.

log(args,

*kwargs)：—— Output a log during the session .

notify(target)： —— Put the given session at the end of the queue .

This method is idempotent ; Multiple notifications of the same session are invalid .
Parameters ：target (Union[str, Callable])—— Sessions that need notification . This specifies the appropriate string ( And nox -s Use the same ) Or use function objects .

posargs：—— Used to set upload from the command line to nox Extra parameters for .

python：—— Pass to @nox.session Of Python edition .

run(args, env=None, kwargs)： —— Run a command .

Command must install string list specified , for example ：

You can't pass everything as a string . for example , You can't do that ：
session.run('pytest -k fast tests/')

You can use it. env Set environment variables for commands ：

You can still use it success_codes , tell nox Treat non-zero exit code as success . for example , If you want to pytest Of “tests discovered, but none selected” Mistakes are regarded as success ：

stay Windows On , image del Such built-in commands cannot be called directly , But you can use cmd /c To call them ：

Parameters ：

env (dict or None)—— Environment variable dictionary for exposing to commands . By default , Pass all environment variables .

silent (bool) —— Silent command output , Unless the order fails . The default is False.

success_codes (list, tuple, or None)—— A series of return codes considered successful . By default , Only 0 Considered a success .

external (bool) —— If False( The default value is ), So don't virtualenv The program in the path will give an alarm . If True, No alarm will be given . These alarms can be used --error-on-external-run Turn it into an error . This pair doesn't have virtualenv The conversation has no effect on .

skip(args,

*kwargs)：—— Jump out of the conversation immediately , And randomly record an alarm .

virtualenv：—— Run all commands virtualenv.

modify Noxfile Medium Nox Behavior Nox There are various command line parameters , Can be used to modify its behavior . Some of them can also be found in Noxfile Use in nox.options Appoint . for example , If you want to Nox Of virtualenvs Store in a different directory , You don't need to pass it on to nox：

perhaps , If you want to provide a set of sessions that run by default ：

The following options can be found in Noxfile It is specified in ：

nox.options.envdir Equivalent to designating –envdir.

nox.options.sessions Equivalent to designating -s or –sessions.

nox.options.keywords Equivalent to designating -k or –keywords.

nox.options.reuse_existing_virtualenvs Equivalent to designating –reuse-existing-virtualenvs . By specifying --no-reuse-existing-virtualenvs , You can force it off .

nox.options.stop_on_first_error Equivalent to designating –stop-on-first-error. By specifying --no-stop-on-first-error, You can force it off .

nox.options.error_on_missing_interpreters Equivalent to designating –error-on-missing-interpreters . By specifying --no-error-on-missing-interpreters , You can force it off .

nox.options.error_on_external_run Equivalent to designating –error-on-external-run. By specifying --no-error-on-external-run , You can force it off .

nox.options.report Equivalent to designating –report.

Calling nox when , Any option specified on the command line takes precedence over Noxfile The options specified in . If you specify... On the command line --sessions or --keywords, So in Noxfile Both options specified in will be ignored .

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