.. _micropython_lib: MicroPython libraries ===================== .. warning:: Important summary of this section * MicroPython provides built-in modules that mirror the functionality of the :ref:`Python standard library ` (e.g. :mod:`os`, :mod:`time`), as well as :ref:`MicroPython-specific modules ` (e.g. :mod:`bluetooth`, :mod:`machine`). * Most Python standard library modules implement a subset of the functionality of the equivalent Python module, and in a few cases provide some MicroPython-specific extensions (e.g. :mod:`array`, :mod:`os`) * Due to resource constraints or other limitations, some ports or firmware versions may not include all the functionality documented here. * To allow for extensibility, some built-in modules can be :ref:`extended from Python code ` loaded onto the device filesystem. This chapter describes modules (function and class libraries) which are built into MicroPython. This documentation in general aspires to describe all modules and functions/classes which are implemented in the MicroPython project. However, MicroPython is highly configurable, and each port to a particular board/embedded system may include only a subset of the available MicroPython libraries. With that in mind, please be warned that some functions/classes in a module (or even the entire module) described in this documentation **may be unavailable** in a particular build of MicroPython on a particular system. The best place to find general information of the availability/non-availability of a particular feature is the "General Information" section which contains information pertaining to a specific :term:`MicroPython port`. On some ports you are able to discover the available, built-in libraries that can be imported by entering the following at the :term:`REPL`:: help('modules') 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 :term:`micropython-lib`. .. _micropython_lib_python: Python standard libraries and micro-libraries --------------------------------------------- The following standard Python libraries have been "micro-ified" to fit in with the philosophy of MicroPython. They provide the core functionality of that module and are intended to be a drop-in replacement for the standard Python library. .. toctree:: :maxdepth: 1 array.rst asyncio.rst binascii.rst builtins.rst cmath.rst collections.rst errno.rst gc.rst gzip.rst hashlib.rst heapq.rst io.rst json.rst math.rst os.rst platform.rst random.rst re.rst select.rst socket.rst ssl.rst struct.rst sys.rst time.rst zlib.rst _thread.rst .. _micropython_lib_micropython: MicroPython-specific libraries ------------------------------ Functionality specific to the MicroPython implementation is available in the following libraries. .. toctree:: :maxdepth: 1 bluetooth.rst btree.rst cryptolib.rst deflate.rst framebuf.rst machine.rst micropython.rst neopixel.rst network.rst uctypes.rst mutex.rst uping.rst urequests.rst Libraries specific to the OpenMV Cam ------------------------------------ The following libraries are specific to the OpenMV Cam. .. toctree:: :maxdepth: 1 pyb.rst stm.rst omv.sensor.rst omv.image.rst omv.tf.rst omv.gif.rst omv.mjpeg.rst omv.audio.rst omv.micro_speech.rst omv.display.rst omv.fir.rst omv.tv.rst omv.cpufreq.rst omv.buzzer.rst omv.imu.rst omv.rpc.rst omv.rtsp.rst omv.omv.rst omv.gt911.rst omv.ft5x06.rst omv.tfp410.rst Third-party libraries on the OpenMV Cam --------------------------------------- The following third-party libraries are built-in to your OpenMV Cam's firmware: :mod:`ulab` --- `numpy-like array manipulation library `_ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. module:: ulab :synopsis: numpy-like array manipulation library :mod:`pid` --- `Proportional/Integral/Derivative Control `_ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. module:: pid :synopsis: Proportional/Integral/Derivative Control :mod:`bno055` --- `IMU Driver `_ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. module:: bno055 :synopsis: IMU Driver Examples scripts are located in OpenMV IDE under the ``IMU Shield`` examples folder. :mod:`ssd1306` --- `OLED Driver `_ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. module:: ssd1306 :synopsis: OLED Driver :mod:`tb6612` --- `Stepper Motor Driver `_ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. module:: tb6612 :synopsis: Stepper Motor Driver Examples scripts are located in OpenMV IDE under the ``Motor Shield`` examples folder. :mod:`lsm6dsox` --- `lsm6dsox Driver `_ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. module:: lsm6dsox :synopsis: lsm6dsox Driver :mod:`modbus` --- `modbus protocol library `_ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. module:: modbus :synopsis: modbus protocol library Examples scripts are located in OpenMV IDE under the ``Modbus`` examples folder. :mod:`mqtt` --- `mqtt protocol library `_ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. module:: mqtt :synopsis: mqtt protocol library Examples scripts are located in OpenMV IDE under the ``WiFi Shield`` examples folder. :mod:`vl53l1x` --- `ToF Distance Sensor Driver `_ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. module:: vl53l1x :synopsis: ToF Distance Sensor Driver Examples scripts are located in OpenMV IDE under the ``Distance Shield`` examples folder. .. _micropython_lib_extending: Extending built-in libraries from Python ---------------------------------------- A subset of the built-in modules are able to be extended by Python code by providing a module of the same name in the filesystem. This extensibility applies to the following Python standard library modules which are built-in to the firmware: ``array``, ``binascii``, ``collections``, ``errno``, ``gzip``, ``hashlib``, ``heapq``, ``io``, ``json``, ``os``, ``platform``, ``random``, ``re``, ``select``, ``socket``, ``ssl``, ``struct``, ``time`` ``zlib``, as well as the MicroPython-specific ``machine`` module. All other built-in modules cannot be extended from the filesystem. This allows the user to provide an extended implementation of a built-in library (perhaps to provide additional CPython compatibility or missing functionality). This is used extensively in :term:`micropython-lib`, see :ref:`packages` for more information. The filesystem module will typically do a wildcard import of the built-in module in order to inherit all the globals (classes, functions and variables) from the built-in. In MicroPython v1.21.0 and higher, to prevent the filesystem module from importing itself, it can force an import of the built-in module it by temporarily clearing ``sys.path`` during the import. For example, to extend the ``time`` module from Python, a file named ``time.py`` on the filesystem would do the following:: _path = sys.path sys.path = () try: from time import * finally: sys.path = _path del _path def extra_method(): pass The result is that ``time.py`` contains all the globals of the built-in ``time`` module, but adds ``extra_method``. In earlier versions of MicroPython, you can force an import of a built-in module by appending a ``u`` to the start of its name. For example, ``import utime`` instead of ``import time``. For example, ``time.py`` on the filesystem could look like:: from utime import * def extra_method(): pass This way is still supported, but the ``sys.path`` method described above is now preferred as the ``u``-prefix will be removed from the names of built-in modules in a future version of MicroPython. *Other than when it specifically needs to force the use of the built-in module, code should always use* ``import module`` *rather than* ``import umodule``.