Python 3.11

https://docs.python.org/3.11
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Python 3.11 is a high-level, interpreted programming language known for its simplicity, readability,...
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### Configure package_data and package_dir with source tree structure

Source: https://docs.python.org/3.11/distutils/setupscript.html

Demonstrates directory layout and corresponding setup() configuration for installing package data files using glob patterns and relative package directories.

```text
setup.py
src/
    mypkg/
        __init__.py
        module.py
        data/
            tables.dat
            spoons.dat
            forks.dat

```

```python
setup(...,
      packages=['mypkg'],
      package_dir={'mypkg': 'src/mypkg'},
      package_data={'mypkg': ['data/*.dat']},
      )

```

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

### Configure build_py_2to3 in setup.py

Source: https://docs.python.org/3.11/distutils/apiref.html

Import build_py_2to3 with a fallback to standard build_py, then pass it to cmdclass in setup() to run 2to3 on installed Python files.

```python
try:
    from distutils.command.build_py import build_py_2to3 as build_py
except ImportError:
    from distutils.command.build_py import build_py

```

```python
cmdclass = {'build_py': build_py}

```

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

### Specify command-line scripts in setup()

Source: https://docs.python.org/3.11/distutils/setupscript.html

Provide a list of script files to be installed. Distutils adjusts the first line if it starts with #! and contains 'python' to point to the current interpreter location.

```python
setup(...,
      scripts=['scripts/xmlproc_parse', 'scripts/xmlproc_val']
      )

```

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

### Configure setup() with ext_modules

Source: https://docs.python.org/3.11/distutils/setupscript.html

Demonstrates a complete setup script that builds and packages a single C extension module.

```python
from distutils.core import setup, Extension
setup(name='foo',
      version='1.0',
      ext_modules=[Extension('foo', ['foo.c'])],
      )

```

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

### Run simplified per-user Python installation via CLI

Source: https://docs.python.org/3.11/using/windows.html

Displays a simplified initial install UI with a custom description while disabling customization, launcher installation, and the test suite.

```shell
python-3.9.0.exe InstallAllUsers=0 Include_launcher=0 Include_test=0
    SimpleInstall=1 SimpleInstallDescription="Just for me, no test suite."

```

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

### Install Python 2.5.1 on OpenBSD i386 using pkg_add

Source: https://docs.python.org/3.11/using/unix.html

Example command to install Python 2.5.1 on OpenBSD for the i386 architecture via an FTP mirror.

```shell
pkg_add ftp://ftp.openbsd.org/pub/OpenBSD/4.2/packages/i386/python-2.5.1p2.tgz

```

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

### Manage patches using start and stop in setUp and tearDown

Source: https://docs.python.org/3.11/library/unittest.mock-examples.html

Control patch lifecycles explicitly within setUp and tearDown methods using patcher.start() and patcher.stop().

```python
>>> class MyTest(unittest.TestCase):
...     def setUp(self):
...         self.patcher = patch('mymodule.foo')
...         self.mock_foo = self.patcher.start()
...
...     def test_foo(self):
...         self.assertIs(mymodule.foo, self.mock_foo)
...
...     def tearDown(self):
...         self.patcher.stop()
...
>>> MyTest('test_foo').run()
```

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

### Build and install Python from source

Source: https://docs.python.org/3.11/using/unix.html

Executes the standard Unix compilation and installation sequence. Note that `make install` can overwrite or masquerade the `python3` binary; `make altinstall` is recommended instead if you only want to install `_exec_prefix_/bin/python_version_`.

```shell
./configure
make
make install

```

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

### Create virtual environment and install wheel

Source: https://docs.python.org/3.11/library/importlib.metadata.html

Sets up a fresh virtual environment and installs the wheel package using pip.

```shell
$ python -m venv example
$ source example/bin/activate
(example) $ python -m pip install wheel

```

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

### Start Python 3.11 Interpreter from Shell

Source: https://docs.python.org/3.11/tutorial/interpreter.html

Starts the Python 3.11 interactive interpreter when /usr/local/bin or the installation folder is in the shell search path.

```shell
python3.11

```

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

### List all ./configure options with --help

Source: https://docs.python.org/3.11/using/configure.html

Displays all available configuration options for the `./configure` build script.

```shell
./configure --help

```

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

### List command options using --help

Source: https://docs.python.org/3.11/distutils/configfile.html

Runs the setup.py help flag for a specific Distutils command to inspect available options. Command-line options using hyphens correspond to underscores in setup.cfg.

```shell
$ python setup.py --help build_ext
[...]
Options for 'build_ext' command:
  --build-lib (-b)     directory for compiled extension modules
  --build-temp (-t)    directory for temporary files (build by-products)
  --inplace (-i)       ignore build-lib and put compiled extensions into the
                       source directory alongside your pure Python modules
  --include-dirs (-I)  list of directories to search for header files
  --define (-D)        C preprocessor macros to define
  --undef (-U)         C preprocessor macros to undefine
  --swig-opts          list of SWIG command line options
[...]

```

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

### Override installation base directory via --install-base

Source: https://docs.python.org/3.11/install/index.html

Demonstrates supplying a different installation base directory when executing the setup script.

```shell
python setup.py install --install-base=/tmp

```

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

### Configure unattended installation using unattend.xml

Source: https://docs.python.org/3.11/using/windows.html

Place this unattend.xml file alongside the installer executable to automatically pass configuration values for unattended setups.

```xml
<Options>
    <Option Name="InstallAllUsers" Value="no" />
    <Option Name="Include_launcher" Value="0" />
    <Option Name="Include_test" Value="no" />
    <Option Name="SimpleInstall" Value="yes" />
    <Option Name="SimpleInstallDescription">Just for me, no test suite</Option>
</Options>

```

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

### Configure setup.py to build multiple extension modules

Source: https://docs.python.org/3.11/extending/newtypes_tutorial.html

Update setup.py to define and build both custom and custom2 C extension modules.

```python
from distutils.core import setup, Extension
setup(name="custom", version="1.0",
      ext_modules=[
         Extension("custom", ["custom.c"]),
         Extension("custom2", ["custom2.c"]),
         ])

```

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

### Define a setup script with distutils.core.setup

Source: https://docs.python.org/3.11/distutils/setupscript.html

Configure package metadata and specify package lists using distutils.core.setup(). Use slash-separated pathnames in Distutils arguments for platform portability.

```python
#!/usr/bin/env python

from distutils.core import setup

setup(name='Distutils',
      version='1.0',
      description='Python Distribution Utilities',
      author='Greg Ward',
      author_email='gward@python.net',
      url='https://www.python.org/sigs/distutils-sig/',
      packages=['distutils', 'distutils.command'],
     )

```

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

### Build extension using setup.py

Source: https://docs.python.org/3.11/extending/newtypes_tutorial.html

Compiles the C extension from the shell.

```shell
$ python setup.py build

```

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

### tracemalloc.start(nframe=1)

Source: https://docs.python.org/3.11/library/tracemalloc.html

Starts tracing Python memory allocations by installing hooks on memory allocators.

```APIDOC
### Function
`tracemalloc.start(nframe: int = 1)`

### Description
Start tracing Python memory allocations: install hooks on Python memory allocators. Collected tracebacks of traces will be limited to `nframe` frames.

### Parameters
- **nframe** (`int`, optional) - Number of frames to store. Must be greater than or equal to `1`. Default is `1`.
```

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

### test.support.import_helper.modules_setup()

Source: https://docs.python.org/3.11/library/test.html

Returns a copy of sys.modules.

```APIDOC
## test.support.import_helper.modules_setup()

### Description
Return a copy of `sys.modules`.
```

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

### distutils.core.run_setup

Source: https://docs.python.org/3.11/distutils/apiref.html

Runs a setup script in a controlled environment and returns the resulting Distribution instance.

```APIDOC
## Function: distutils.core.run_setup(script_name[, script_args=None, stop_after='run'])

### Description
Run a setup script in a somewhat controlled environment, and return the `distutils.dist.Distribution` instance that drives things. This is useful if you need to find out the distribution meta-data (passed as keyword args from `script` to `setup()`), or the contents of the config files or command-line.

### Parameters
- **script_name** (string) - A file that will be read and run with `exec()`. `sys.argv[0]` will be replaced with `script_name` for the duration of the call.
- **script_args** (list of strings, optional) - If supplied, `sys.argv[1:]` will be replaced by `script_args` for the duration of the call. Defaults to `None`.
- **stop_after** (string, optional) - Tells `setup()` when to stop processing. Defaults to `'run'`.
  - `'init'`: Stop after the `Distribution` instance has been created and populated with keyword arguments to `setup()`.
  - `'config'`: Stop after config files have been parsed (and data stored in the `Distribution` instance).
  - `'commandline'`: Stop after the command-line (`sys.argv[1:]` or `script_args`) has been parsed (and data stored in the `Distribution` instance).
  - `'run'`: Stop after all commands have been run (the same as if `setup()` had been called in the usual way).

### Returns
- **distutils.dist.Distribution** - The distribution instance that drives things.
```

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

### Example PATH environment variable value on Windows

Source: https://docs.python.org/3.11/using/windows.html

Shows an example of a Windows PATH environment variable string containing standard system directories alongside a Python installation path separated by semicolons.

```text
C:\WINDOWS\system32;C:\WINDOWS;C:\Program Files\Python 3.9

```

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

### Get distribution metadata keys with list(metadata())

Source: https://docs.python.org/3.11/library/importlib.metadata.html

Inspects the available metadata keys for an installed distribution package.

```python
>>> list(metadata('wheel'))  
['Metadata-Version', 'Name', 'Version', 'Summary', 'Home-page', 'Author', 'Author-email', 'Maintainer', 'Maintainer-email', 'License', 'Project-URL', 'Project-URL', 'Project-URL', 'Keywords', 'Platform', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Classifier', 'Requires-Python', 'Provides-Extra', 'Requires-Dist', 'Requires-Dist']

```

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

### Define basic C extension in setup.py

Source: https://docs.python.org/3.11/extending/building.html

Defines a minimal setup.py driver script for building an extension module from a single source file demo.c.

```python
from distutils.core import setup, Extension

module1 = Extension('demo',
                    sources = ['demo.c'])

setup (name = 'PackageName',
       version = '1.0',
       description = 'This is a demo package',
       ext_modules = [module1])

```

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

### Import secrets for XKCD-style passphrase generation

Source: https://docs.python.org/3.11/library/secrets.html

Starts the setup for generating an XKCD-style passphrase using the secrets module.

```python
import secrets

```

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

### distutils.core.Distribution

Source: https://docs.python.org/3.11/distutils/apiref.html

Describes how to build, install, and package up a Python software package. An instance of this class is created by the setup() function.

```APIDOC
## class distutils.core.Distribution

### Description
Describes how to build, install and package up a Python software package. Created by the `setup()` function.
```

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

### Get a Distribution instance using distribution()

Source: https://docs.python.org/3.11/library/importlib.metadata.html

Obtain a Distribution instance representing the metadata for an installed Python distribution package.

```python
>>> from importlib.metadata import distribution  
>>> dist = distribution('wheel')  

```

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

### Define a minimal setup script for a single module

Source: https://docs.python.org/3.11/distutils/introduction.html

Configures a basic setup.py script with module metadata and module names for distribution. Keyword arguments supply package metadata and module information.

```python
from distutils.core import setup
setup(name='foo',
      version='1.0',
      py_modules=['foo'],
      )

```

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

### Define basic setup.cfg syntax

Source: https://docs.python.org/3.11/distutils/configfile.html

Demonstrates the general INI-style structure of a Distutils configuration file. Blank lines and comments starting with '#' are ignored, and multi-line values can be indented.

```ini
[command]
option=value
...

```

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

### Check Python launcher availability with py

Source: https://docs.python.org/3.11/using/windows.html

Starts the latest installed Python version using the Python launcher. Any additional command-line arguments are forwarded directly to Python.

```shell
py

```

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

### os.startfile(path[, operation][, arguments][, cwd][, show_cmd])

Source: https://docs.python.org/3.11/library/os.html

Starts a file with its associated application on Windows. Can specify command verbs, additional arguments, working directory, and window style.

```APIDOC
## os.startfile(path[, operation][, arguments][, cwd][, show_cmd])

### Description
Start a file with its associated application on Windows. When operation is not specified or `'open'`, this acts like double-clicking the file in Windows Explorer. Returns as soon as the associated application is launched.

### Syntax
```python
os.startfile(path[, operation][, arguments][, cwd][, show_cmd])
```

### Parameters
- **path** - Required. The path to the file or directory to open.
- **operation** - Optional. Command verb specifying what should be done (e.g., `'open'`, `'print'`, `'edit'`, `'explore'`, `'find'`).
- **arguments** - Optional. String of arguments passed when launching an application.
- **cwd** - Optional. Absolute path specifying the working directory.
- **show_cmd** - Optional. Integer to override default window style, matching Win32 `ShellExecute()` values.

### Exceptions
- **NotImplementedError**: Raised if the Win32 `ShellExecute()` function cannot be resolved.

### Audit Events
- `os.startfile` with arguments `path`, `operation`
- `os.startfile/2` with arguments `path`, `operation`, `arguments`, `cwd`, `show_cmd`

### Availability
Windows.
```

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

### Vary starting indentation columns in doctest

Source: https://docs.python.org/3.11/library/doctest.html

Shows that doctest ignores leading indentation in example blocks; leading whitespace corresponding to the initial prompt line is stripped from expected output.

```python
>>> assert "Easy!"
      >>> import math
          >>> math.floor(1.9)
          1

```

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

### Configure setup.py to build custom extension

Source: https://docs.python.org/3.11/extending/newtypes_tutorial.html

Defines the distutils setup script for compiling custom.c into a C extension.

```python
from distutils.core import setup, Extension
setup(name="custom", version="1.0",
      ext_modules=[Extension("custom", ["custom.c"])])

```

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

### Run test discovery with start directory and pattern options

Source: https://docs.python.org/3.11/library/unittest.html

Demonstrates equivalent ways to specify start directory (-s) and file matching pattern (-p) using flags or positional arguments.

```shell
python -m unittest discover -s project_directory -p "*_test.py"
python -m unittest discover project_directory "*_test.py"

```

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

### Install a distributed module

Source: https://docs.python.org/3.11/distutils/introduction.html

Installs the unpacked module into the third-party modules directory of the Python installation.

```shell
python setup.py install

```

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

### Use and install custom opener with urllib.request

Source: https://docs.python.org/3.11/howto/urllib2.html

Fetch a URL using a configured opener instance or install it globally. Once installed, all subsequent calls to urllib.request.urlopen will use the installed opener.

```python
# use the opener to fetch a URL
opener.open(a_url)

# Install the opener.
# Now all calls to urllib.request.urlopen use our opener.
urllib.request.install_opener(opener)
```

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

### Configure setup.py for multiple modules with py_modules

Source: https://docs.python.org/3.11/distutils/examples.html

Specifies multiple module files foo and bar in a list passed to py_modules.

```python
from distutils.core import setup
setup(name='foobar',
      version='1.0',
      py_modules=['foo', 'bar'],
      )

```

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

### Install packages from requirements.txt with pip install -r

Source: https://docs.python.org/3.11/tutorial/venv.html

Installs all dependencies listed in a requirements file into the virtual environment.

```shell
(tutorial-env) $ python -m pip install -r requirements.txt
Collecting novas==3.1.1.3 (from -r requirements.txt (line 1))
  ...
Collecting numpy==1.9.2 (from -r requirements.txt (line 2))
  ...
Collecting requests==2.7.0 (from -r requirements.txt (line 3))
  ...
Installing collected packages: novas, numpy, requests
  Running setup.py install for novas
Successfully installed novas-3.1.1.3 numpy-1.9.2 requests-2.7.0

```

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

### Create a source distribution with sdist on Windows

Source: https://docs.python.org/3.11/distutils/introduction.html

Runs setup.py directly from a Windows command prompt to create an sdist archive.

```bat
setup.py sdist

```

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

### Build and distribute C extensions with setup.py

Source: https://docs.python.org/3.11/whatsnew/2.0.html

Defines an Extension instance specifying macros, include directories, and source files to compile C extensions.

```python
from distutils.core import setup, Extension

expat_extension = Extension('xml.parsers.pyexpat',
     define_macros = [('XML_NS', None)],
     include_dirs = [ 'extensions/expat/xmltok',
                      'extensions/expat/xmlparse' ],
     sources = [ 'extensions/pyexpat.c',
                 'extensions/expat/xmltok/xmltok.c',
                 'extensions/expat/xmltok/xmlrole.c', ]
       )
setup (name = "PyXML", version = "0.5.4",
       ext_modules =[ expat_extension ] )

```

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

### Configure site-packages paths using foo.pth and bar.pth

Source: https://docs.python.org/3.11/library/site.html

Demonstrates how .pth configuration files (foo.pth and bar.pth) add directory paths to sys.path in alphabetical file order, skipping nonexistent directories like bletch.

```text
# foo package configuration

foo
bar
bletch

```

```text
# bar package configuration

bar

```

```text
/usr/local/lib/pythonX.Y/site-packages/bar
/usr/local/lib/pythonX.Y/site-packages/foo

```

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

### Export installed packages with pip freeze

Source: https://docs.python.org/3.11/tutorial/venv.html

Produces a list of installed packages formatted for pip install and writes it to a requirements.txt file.

```shell
(tutorial-env) $ python -m pip freeze > requirements.txt
(tutorial-env) $ cat requirements.txt
novas==3.1.1.3
numpy==1.9.2
requests==2.7.0

```

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

### Invoke xmlrpc.server demo from command line

Source: https://docs.python.org/3.11/library/xmlrpc.server.html

Executes the built-in ExampleService server demo using Python's module execution CLI flag.

```shell
python -m xmlrpc.server

```

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

### Upgrade a package to the latest version with pip install --upgrade

Source: https://docs.python.org/3.11/tutorial/venv.html

Upgrades an existing installed package to its latest version, replacing previous installations.

```shell
(tutorial-env) $ python -m pip install --upgrade requests
Collecting requests
Installing collected packages: requests
  Found existing installation: requests 2.6.0
    Uninstalling requests-2.6.0:
      Successfully uninstalled requests-2.6.0
Successfully installed requests-2.7.0

```

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

### Execute setup.py build with custom build-base and force flags

Source: https://docs.python.org/3.11/install/index.html

Command-line equivalent for setting build-base and force options in the build section of a configuration file.

```bash
python setup.py build --build-base=blib --force

```
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