This chapter described modules (function and class libraries) which are built

into MicroPython. There are few categories of modules:

* Modules which implement subset of standard Python functionality and are not

intended to be extended by a user.

* Modules which are implement subset of Python functionality, with a provision

for extension by a user (via Python code).

* Modules which implement MicroPython extensions to Python standard libraries.

* Modules specific to a particular port and thus not portable.

Note about the availability of modules and their contents: This documentation

in general aspires to describe all modules and functions/classes which are

implemented in MicroPython. However, MicroPython is highly configurable, and

each port to a particular board/embedded system makes available only a subset

of MicroPython libraries. For officially supported ports, there is an effort

to either filter out non-applicable items, or mark individual descriptions

with "Availability:" clauses describing which ports provide a given feature.

With that in mind, please still be ready to a fact that some function/class

in a module, or even entire module, described in this documentation, may be

not available in a particular build of MicroPython on a particular board. The

best place to find a general information of the availability/non-availability

of a particular feature is "General Information" secton which contains

information pertaining to a specific port.

Beyond the built-in libraries described in this documentation, many more

modules from the Python standard library, as well as further MicroPython

extensions to it, can be found in the `micropython-lib repository