.. _memmap-getting-started:

Getting started
===============

Create mappings through :class:`MemoryMap` factory methods rather than by
constructing the extension type directly.

Anonymous mapping
-----------------

.. code-block:: python

   from scikitplot.memmap import MemoryMap

   with MemoryMap.create_anonymous(4096) as mm:
       mm.write(b"hello", 0)
       assert mm.read(5, 0) == b"hello"

File-backed mapping
-------------------

File-backed mappings accept an **open file descriptor**, a byte offset and a
mapping size. Offsets must satisfy the platform page-alignment requirement.
Keep file ownership clear: mapping a descriptor does not turn arbitrary binary
data into a parsed object.

Use :func:`py_get_page_size` and :func:`py_is_page_aligned` when calculating
portable offsets.