Python/libs/ConfigMix: doc/introduction.rst annotate

annotate doc/introduction.rst @ 117:c5b638f9c607

- More on getting variable values - Reorga of the variable documentation

author	Franz Glasner <hg@dom66.de>
date	Thu, 29 Mar 2018 08:58:34 +0200
parents	a5339d39af5c
children	21d92ff8cf31

rev	line source
94 2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	1 .. -- coding: utf-8; indent-tabs-mode: nil; --
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	2
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	3 .. _introduction:
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	4
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	5 Introduction
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	6 ============
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	7
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	8 The configurations can be read from different types of files:
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	9
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	10 - :ref:`YAML files <yaml-files>`
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	11 - :ref:`INI files <ini-files>`
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	12 - :ref:`executable Python scripts <executable-python-scripts>`
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	13
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	14
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	15 .. _yaml-files:
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	16
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	17 YAML Files
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	18 ----------
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	19
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	20 Need the :mod:`yaml` package (e.g. ``pip install pyyaml``)
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	21
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	22 .. note:: All strings are returned as Unicode text strings.
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	23
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	24
97 1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	25 An example is:
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	26
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	27 .. literalinclude:: ../tests/data/conf10.yml
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	28 :language: yaml
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	29
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	30
94 2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	31 .. _ini-files:
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	32
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	33 INI Files
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	34 ---------
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	35
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	36 Read the file and all sections named in parameter `extract` are flattened
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	37 into the resulting dictionary. By default the section named ``config`` is
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	38 used.
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	39
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	40 Normally all values are returned as Unicode text strings.
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	41 But values can be annotated and therefore interpreted as other types:
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	42
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	43 ``:int:``
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	44 The value is handled in the same way as a Python :class:`int`
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	45 literal
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	46
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	47 ``:float:``
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	48 The value is interpreted as :class:`float`
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	49
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	50 ``:bool:``
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	51 The resulting value is a :class:`bool` where
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	52
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	53 ``1``, ``true``, ``yes``, ``on``
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	54 yield a Python ``True``
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	55
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	56 ``0``, ``false``, ``no``, ``off``
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	57 yield a Python ``False``
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	58
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	59 The evaluation is done case-insensitively.
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	60
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	61 .. note:: All strings are returned as Unicode text strings.
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	62
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	63 .. note:: Contrary to the behaviour of the standard Python :mod:`configparser`
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	64 module the INI file reader is case-sensitive.
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	65
97 1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	66 The example INI style configuration below yields an equivalent
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	67 configuration to the YAML configuration above:
94 2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	68
97 1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	69 .. literalinclude:: ../tests/data/conf10.ini
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	70 :language: ini
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	71
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	72 As can be seen in thie example -- INI file internal value interpolation
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	73 is done as in Python's standard :mod:`configparser` module.
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	74
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	75 This example also illustrates how INI sections are used to build a
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	76 tree-ish configuration dictionary.
94 2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	77
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	78
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	79 .. _executable-python-scripts:
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	80
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	81 Executable Python Scripts
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	82 -------------------------
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	83
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	84 What will be exported:
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	85
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	86 1. If loading is done with the `extract` parameter only the given keys are
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	87 extracted from the script.
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	88
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	89 2. Otherwise it is checked if the scripts defines an ``__all__``
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	90 sequence. If there is one it's contents are the keys to be
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	91 extracted.
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	92
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	93 3. If there is no ``__all__`` object all names not starting with an
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	94 underscore ``_`` are found.
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	95
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	96 This is analogous to as Python modules behave when importing them with
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	97 ``from module import *``.
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	98
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	99 .. note:: The Python configuration files are evaluated with ``exec`` and not
2b79ddc0f92b Begin a basic introduction chapter Franz Glasner <hg@dom66.de> parents: diff changeset	100 imported.
97 1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	101
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	102 The example configuration by Python script below yields an equivalent
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	103 configuration to the YAML configuration above:
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	104
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	105 .. literalinclude:: ../tests/data/conf10.py
1b4d95f60650 Build a tree-ish configuration from an INI style configuration file Franz Glasner <hg@dom66.de> parents: 94 diff changeset	106 :language: python
114 aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	107
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	108
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	109 .. _loading-and-merging:
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	110
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	111 Loading and Merging
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	112 -------------------
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	113
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	114 Basic usage of the API is as follows in this example::
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	115
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	116 import configmix
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	117
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	118 #
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	119 # Note: With conf10 merging is rather pointless because the tree
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	120 # files # are really the same configuration. But is doesn't harm
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	121 # also here.
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	122 #
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	123 config = configmix.load("conf10.yml", "conf10.ini", "conf10.py")
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	124
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	125 # Get a -- possibly interpolated -- configuration variable's value
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	126 value1 = config.getvar_s("key1")
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	127
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	128 # Get a -- possibly interpolated -- variable from within the tree
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	129 value2 = config.getvar_s("tree1.tree2.key4")
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	130
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	131
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	132 The filenames of the configuration files must have the extensions
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	133 (case-insensitively):
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	134
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	135 ``.py``
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	136 for Python configuration files
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	137
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	138 ``.yml`` or ``.yaml``
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	139 for YAML configuration files
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	140
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	141 ``.ini``
aa0c61e79660 Add a documentation section about basic API usage: loading (and merging) Franz Glasner <hg@dom66.de> parents: 97 diff changeset	142 for INI configuration files
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	143
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	144
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	145 .. _getting-values:
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	146
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	147 Getting configuration variables
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	148 -------------------------------
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	149
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	150 Get a -- possibly expanded -- configuration variable's value with::
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	151
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	152 value1 = config.getvar_s("key1")
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	153
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	154 Get a raw configuration variable's value with::
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	155
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	156 value1_raw = config.getvar("key1")
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	157
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	158 Because the configuration is not only a plain list of but a tree of
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	159 key-value pairs you will want to fetch them by separating the individual
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	160 level keys with a point ``.``.
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	161
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	162 Looking at the example in chapter :ref:`yaml-files` -- when calling
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	163 ``config.getvar_s("tree1.tree2.key4")`` you will get the value
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	164 ``get this as `tree1.tree2.key4'``.
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	165
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	166 This is true for both methods :py:meth:`.Configuration.getvar` and
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	167 :py:meth:`.Configuration.getvar_s`.
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	168
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	169 Both methods also perform :ref:`variable-expansion` and handle
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	170 :ref:`variable-namespaces`. Filtering is not supported. So -- the
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	171 variable name arguments of :py:meth:`.Configuration.getvar` and
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	172 :py:meth:`.Configuration.getvar_s` are of the form
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	173 ``[namespace:]variable``.
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	174
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	175
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	176 .. _variable-namespaces:
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	177
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	178 Variable Namespaces
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	179 -------------------
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	180
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	181 Currently there are 4 namespaces:
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	182
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	183 1. The unnamed namespace (which is also default).
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	184
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	185 All the configuration variables are part of this namespace.
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	186
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	187 2. The namespace ``OS``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	188
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	189 Available functions:
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	190
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	191 ``cwd``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	192 Contains the current working directory of the process
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	193
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	194 3. The namespace ``ENV``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	195
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	196 This namespace contains all the environment variables as they are
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	197 available from :py:data:`os.environ`.
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	198
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	199 4. The namespace ``PY``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	200
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	201 Contains selected values from the running Python:
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	202
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	203 ``version``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	204 The return value of :py:func:`platform.python_version`
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	205
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	206 ``version_maj_min``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	207 Just the major and minor version of the running Python
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	208 (``.`` separated)
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	209
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	210 ``version_maj``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	211 Just the major version of the running Python
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	212
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	213 ``implementation``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	214 The return value of :py:func:`platform.python_implementation`
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	215
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	216
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	217 Examples
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	218 ~~~~~~~~
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	219
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	220 ::
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	221
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	222 config.getvar("OS:cwd")
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	223
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	224 yields the current working directory as :py:func:`os.getcwd` does.
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	225
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	226
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	227 .. _variable-expansion:
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	228
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	229 Variable Expansion
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	230 ------------------
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	231
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	232 Configuration variable values that are read with
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	233 :py:meth:`.Configuration.getvar_s` are subject to variable
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	234 expansion. The general syntactic pattern for this is::
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	235
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	236 {{[namespace:]variable[\|filter[\|filter...]]}}
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	237
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	238 I.e.: between double curly braces an optional `namespace` name followed by
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	239 a colon ``:``, the `variable` and then zero or more filters, each one
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	240 introduced by a pipe symbol ``\|``.
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	241
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	242 Variables are expanded lately at runtime -- exactly when calling
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	243 :py:meth:`.Configuration.getvar_s` or :py:meth:`.Configuration.getvar`.
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	244
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	245
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	246 Filter functions
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	247 ~~~~~~~~~~~~~~~~
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	248
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	249 Interpolated values can be processed through a series of filter functions::
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	250
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	251 {{my.variable\|filter1\|filter2}}
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	252
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	253 Available filter functions are:
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	254
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	255 ``urlquote``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	256
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	257 ``saslprep``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	258
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	259 ``normpath``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	260
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	261 ``abspath``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	262
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	263 ``posixpath``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	264
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	265 ``lower``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	266
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	267 ``upper``
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	268
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	269
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	270 Examples
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	271 ~~~~~~~~
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	272
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	273 ::
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	274
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	275 {{OS:cwd\|posixpath}}
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	276
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	277 expands to the current working directory as POSIX path: on Windows all
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	278 backslashes are replaced by forward slashes.
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	279
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	280 ::
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	281
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	282 {{ENV:PATH}}
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	283
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	284 expands to the current search path from the process environment.
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	285
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	286 ::
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	287
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	288 {{PY:version}}
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	289
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	290 expands to the current running Python version (e.g. ``3.6.4``).
115 a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	291
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	292 ::
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	293
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	294 {{PY::implementation\|upper}}
a5339d39af5c Begin the documentation of variables and its expansion Franz Glasner <hg@dom66.de> parents: 114 diff changeset	295
117 c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	296 expands to something like ``CPYTHON`` when using the standard Python
c5b638f9c607 - More on getting variable values Franz Glasner <hg@dom66.de> parents: 115 diff changeset	297 interpreter written in C.

Mercurial > hgrepos > Python > libs > ConfigMix

annotate doc/introduction.rst @ 117:c5b638f9c607