1. Introduction

1.1. Functionality

Class nocaselist.NocaseList is a case-insensitive list that preserves the lexical case of its items.

Example:

$ python
>>> from nocaselist import NocaseList
>>> list1 = NocaseList(['Alpha', 'Beta'])

>>> print(list1)  # Any access is case-preserving
['Alpha', 'Beta']

>>> 'ALPHA' in list1  # Any lookup or comparison is case-insensitive
True

The NocaseList class supports the functionality of the built-in list class of Python 3.8 on all Python versions it supports (except for being case-insensitive, of course). This includes the clear() and copy() methods added in Python 3.3 to the built-in list class.

1.2. Supported environments

The package does not have any dependencies on the type of operating system and is regularly tested in CI systems on the following operating systems:

  • Ubuntu, native Windows, CygWin, OS-X / macOS

The package is supported on the following Python versions:

  • Python: 2.7, 3.4 and all higher 3.x versions

1.3. Installing

  • Prerequisites:

    • The Python environment into which you want to install must be the current Python environment, and must have at least the following Python packages installed:
      • setuptools
      • wheel
      • pip
  • Install the nocaselist package and its prerequisite Python packages into the active Python environment:

    $ pip install nocaselist
    

1.4. Installing a different version

The examples in the previous sections install the latest version of nocaselist that is released on PyPI. This section describes how different versions of nocaselist can be installed.

  • To install an older released version of nocaselist, Pip supports specifying a version requirement. The following example installs nocaselist version 0.1.0 from PyPI:

    $ pip install nocaselist==0.1.0
    
  • If you need to get a certain new functionality or a new fix that is not yet part of a version released to PyPI, Pip supports installation from a Git repository. The following example installs nocaselist from the current code level in the master branch of the nocaselist repository:

    $ pip install git+https://github.com/pywbem/nocaselist.git@master#egg=nocaselist
    

1.5. Verifying the installation

You can verify that nocaselist is installed correctly by importing the package into Python (using the Python environment you installed it to):

$ python -c "import nocaselist; print('ok')"
ok

1.5.1. Package version

The version of the nocaselist package can be accessed by programs using the nocaselist.__version__ variable:

nocaselist._version.__version__ = '1.0.4'

The full version of this package including any development levels, as a string.

Possible formats for this version string are:

  • “M.N.P.dev1”: Development level 1 of a not yet released version M.N.P
  • “M.N.P”: A released version M.N.P

Note: For tooling reasons, the variable is shown as nocaselist._version.__version__, but it should be used as nocaselist.__version__.

1.5.2. Compatibility and deprecation policy

The nocaselist project uses the rules of Semantic Versioning 2.0.0 for compatibility between versions, and for deprecations. The public interface that is subject to the semantic versioning rules and specificically to its compatibility rules are the APIs and commands described in this documentation.

The semantic versioning rules require backwards compatibility for new minor versions (the ‘N’ in version ‘M.N.P’) and for new patch versions (the ‘P’ in version ‘M.N.P’).

Thus, a user of an API or command of the nocaselist project can safely upgrade to a new minor or patch version of the nocaselist package without encountering compatibility issues for their code using the APIs or for their scripts using the commands.

In the rare case that exceptions from this rule are needed, they will be documented in the Change log.

Occasionally functionality needs to be retired, because it is flawed and a better but incompatible replacement has emerged. In the nocaselist project, such changes are done by deprecating existing functionality, without removing it immediately.

The deprecated functionality is still supported at least throughout new minor or patch releases within the same major release. Eventually, a new major release may break compatibility by removing deprecated functionality.

Any changes at the APIs or commands that do introduce incompatibilities as defined above, are described in the Change log.

Deprecation of functionality at the APIs or commands is communicated to the users in multiple ways:

  • It is described in the documentation of the API or command
  • It is mentioned in the change log.
  • It is raised at runtime by issuing Python warnings of type DeprecationWarning (see the Python warnings module).

Since Python 2.7, DeprecationWarning messages are suppressed by default. They can be shown for example in any of these ways:

  • By specifying the Python command line option: -W default
  • By invoking Python with the environment variable: PYTHONWARNINGS=default

It is recommended that users of the nocaselist project run their test code with DeprecationWarning messages being shown, so they become aware of any use of deprecated functionality.

Here is a summary of the deprecation and compatibility policy used by the nocaselist project, by version type:

  • New patch version (M.N.P -> M.N.P+1): No new deprecations; no new functionality; backwards compatible.
  • New minor release (M.N.P -> M.N+1.0): New deprecations may be added; functionality may be extended; backwards compatible.
  • New major release (M.N.P -> M+1.0.0): Deprecated functionality may get removed; functionality may be extended or changed; backwards compatibility may be broken.

1.5.3. Python namespaces

This documentation describes only the external APIs of the nocaselist project, and omits any internal symbols and any sub-modules.