Installation and customization

PyPI (recommended)

APSW is on PyPI at https://pypi.org/project/apsw/

It can be installed in the same way as other packages:

python3 -m pip install apsw

When you install from PyPI:

The corresponding SQLite version is embedded privately inside and not affected by or visible to the rest of the machine or even the rest of the process.

This means other modules and libraries will continue using whatever SQLite they would have before. For example Core Data on MacOS uses SQLite, but will not know of or be affected by the SQLite inside APSW.
All extensions are enabled, except ICU.
SQLITE_ENABLE_COLUMN_METADATA is enabled, providing Cursor.description_full

The PyPI releases include pre-built binaries for common platforms. If yours is not covered, then pip will download the source release and automatically compile with the same settings. It will require a C compiler and the Python development header files.

Encryption

APSW compiled against SQLite with SQLite3MultipleCiphers is available via its author at https://pypi.org/project/apsw-sqlite3mc/

Linux/BSD provided

Most Linux & BSD distributions have packaged APSW which may trail the SQLite and APSW releases by a year, or more. The distribution provided APSW uses the system wide SQLite library.

Debian	Install python3-apsw
Fedora	Install python3-apsw
Ubuntu	Install python3-apsw
Gentoo	Install dev-python/apsw
Arch	Install python-apsw
FreeBSD	databases/py-apsw in Ports

There is a full list (150+) of distributions, the package name for APSW, and what APSW version they are currently on.

Source

It is recommended you get the source from Github releases. If you get the source from PyPi then ensure you edit the setup.apsw file inside.

apsw-3.47.2.0.zip (Source, includes this HTML Help)
apsw-3.47.2.0.cosign-bundle cosign signature

Verifying your download

Github source releases are digitally signed so you can verify they have not been tampered with, and were produced by the project maintainer.

Sigstore is used via the cosign tool. Download the corresponding cosign bundle which contains the signature.

Verify

Install cosign if you don’t have it already. It is available for a wide variety of platforms including Linux, MacOS, and Windows.

Checking the signature needs to provide the source release, the cosign bundle, the maintainer id, and issuer. The command is all one line shown here across multiple lines for clarity.
$ cosign verify-blob apsw-3.47.2.0.zip                           \
    --bundle apsw-3.47.2.0.cosign-bundle                         \
    --certificate-identity=rogerb@rogerbinns.com                 \
    --certificate-oidc-issuer=https://github.com/login/oauth
Verified OK
Check for a success exit code, and verified message.

Building and customization

APSW is configured for standard building (PEP 518)

$ python3 -m build

You will need to update the MANIFEST first if you are providing your own SQLite, or if you are providing a setup.apsw with custom configuration. setuptools is used to compile the extension. You can use it directly instead by invoking setup.py.

Build process

A series of commands and options are given to setup.py in this pattern:

python setup.py cmdone --option --option value cmdtwo --option \
   cmdthree --option --option value

The only necessary command is build. You can get help by –help:

python setup.py build --help

Each command takes options which can be specified on the command line, or in a configuration file named setup.cfg or setup.apsw. The leading double dash on options is omitted, and dashes inside should become underscores.

# This is used with pypi source and binary builds

[build]
# download corresponding sqlite release
fetch = True
# all extensions included
enable_all_extensions = True
# ... except icu (not abi stable)
omit = icu
# for Cursor.description_full
enable = COLUMN_METADATA

SQLite options

It is important to understand SQLite’s compile time options. They provide control over functionality and APIs included or excluded from SQLite.

APSW needs to know the options chosen so it can adapt. For example if extension loading is omitted from SQLite then APSW also needs to omit the same functionality, otherwise compilation or linking will fail.

Finding SQLite

APSW can fetch SQLite as detailed below, and places it in a sqlite3/ subdirectory. You can place your own SQLite in that directory. If there is a sqlite3.c (ie the amalgamation) then it will be statically included inside APSW. A compiled SQLite will be picked up if present. If none of that is present, then the standard compiler locations are used (eg /usr/include on Unix).

If sqlite3/sqlite3config.h is present it is included before sqlite3/sqlite3.c. It is a good location to put platform configuration which APSW’s fetch does automatically by running configure.

setup.py commands and their options

These are the relevant setup.py commands and their relevant options.

build

Does the complete build. This will invoke build_ext - use only one of build or build_ext.

`--fetch`	Fetches the corresponding SQLite version
`--enable-all-extensions`	Enables all the standard extensions
`--enable`	A comma separated list of options to enable that are normally off omitting the `SQLITE_ENABLE` prefix. They will be uppercased. eg `--enable column_metadata,fts5`
`--omit`	A comma separated list of options to omit that are normally enabled omitting the `SQLITE_OMIT` prefix. They will be uppercased. eg `--omit automatic_index`

fetch

This provides more fine grained control over what is fetched.

`--version`	Specify an explicit version of SQLite to fetch
`--fetch-sqlite`	Downloads the SQLite amalgamation
`--all`	Downloads all SQLite components other than the amalgamation. Over time this has included additional extensions and SQLite functions, but currently is nothing.
`--missing-checksum-ok`	APSW includes checksums of SQLite releases and will fail a fetch if you specify a version for which no checksum is known. This allows proceeding.

build_ext

This performs the compilation of the C code, and provides more control than build.

`--use-system-sqlite-config`	Uses `ctypes` to determine the system wide SQLite library compilation options
`--definevalues`	Additional #defines separated by commas. eg `--definevalues SQLITE_MAX_ATTACHED=37,SQLITE_EXTRA_INIT=mycore_init`
`--enable-all-extensions`	Enables all the standard extensions
`--enable`	A comma separated list of options to enable that are normally off omitting the `SQLITE_ENABLE` prefix. They will be uppercased. eg `--enable column_metadata,fts5`
`--omit`	A comma separated list of options to omit that are normally enabled omitting the `SQLITE_OMIT` prefix. They will be uppercased. eg `--omit automatic_index`
`--apsw-no-old-names`	Excludes old non PEP 8 complaint name aliases from the extension and type stubs.

Pyodide

Pyodide is a web assembly Python distribution that can run in the browser or via NPM. PyPI does not support pyodide binary packages yet, but you can compile your own on a Linux host.

You should first download the source distribution listed at the top of https://pypi.org/project/apsw/#files - the filename ends up being apsw-3.47.0.0.tar.gz in this example. The cibuildwheel tool is used for the building, and is the same tool used for the PyPI builds of APSW.

# Start out with a clean virtual environment
$ python3 -m venv venv
# Get cibuildwheel
$ venv/bin/pip3 install cibuildwheel
# Do the building which will download the necessary compiler and
# Python parts
$ venv/bin/cibuildwheel --platform pyodide apsw-3.47.0.0.tar.gz
# When it has finished the result is in the wheelhouse directory
$ ls wheelhouse/

You will then be able to install the wheel using micropip.

>>> import micropip
>>> await micropip.install("https://url/apsw-3.47.0.0-cp312-cp312-pyodide_2024_0_wasm32.whl")
>>> import apsw

At this point you will be able to use APSW as normal.

Advice for packagers

This is the recommendation for packagers such as Linux and BSD distributions, who want APSW to use the system shared SQLite library.

Use the source file from github releases. Note you should use the zip file including the version number, not the github repository copy at the end. The file is signed and can be verified.

The file also includes a copy of the built documentation in HTML format with no analytics in the doc/ subdirectory.
After extracting the zip, replace the file named setup.apsw that sits alongside setup.py with the following contents:
```
[build_ext]
use_system_sqlite_config = True
```
This will probe the system SQLite shared library for its compilation options. Various C level APIs are included or excluded from the shared library based on those options, so APSW needs to know at compilation time which APIs it can or can’t call.
You can compile APSW using whatever works for your packaging system. APSW complies with the latest Python packaging guidelines and metadata. (The traditional setuptools is the build backend.) You will see lines like the following during build (note the Extracting configuration).
```
running build_ext
Extracting configuration from libsqlite3.so.0
SQLite: Using system sqlite include/libraries
```
pyproject.toml defines a script entry point (command line tool) for apsw which invokes the Shell. It is optional to package this. A man page is included in the man/ directory.

Testing

SQLite itself is extensively tested. It has considerably more code dedicated to testing than makes up the actual database functionality.

APSW includes tests which use the standard Python testing modules to verify correct operation. New code is developed alongside the tests. Reported issues also have test cases to ensure the issue doesn’t happen or doesn’t happen again.:

                Python  /usr/bin/python3 sys.version_info(major=3, minor=12, micro=7, releaselevel='final', serial=0) 64bit ELF
Testing with APSW file  /space/apsw/apsw/__init__.cpython-312-x86_64-linux-gnu.so
          APSW version  3.47.0.0
    SQLite lib version  3.47.0
SQLite headers version  3047000
    Using amalgamation  True
.....................................................................................................................................................................
----------------------------------------------------------------------
Ran 165 tests in 29.844s

OK

The tests also ensure that as much APSW code as possible is executed including alternate paths through the code. 95.5% of the APSW code is executed by the tests. In the source, there is a script that enables extra code that deliberately induces extra conditions such as memory allocation failures, SQLite returning error codes, Python APIs erroring etc. That brings coverage up to 99.6% of the code.

Compiler sanitizers options are also used for further validation.

To ensure compatibility with the various Python versions, a script downloads and compiles all supported Python versions in both debug and release configurations (and 32 and 64 bit) against the APSW and SQLite supported versions running the tests.

In short both SQLite and APSW have a lot of testing!