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Package Assembler#

Create conda packages programmatically without a recipe file.

You can import the package assembler classes and functions from rattler_build:

from rattler_build import assemble_package, collect_files, ArchiveType, FileEntry, PackageOutput

assemble_package#

Create a conda package from files and metadata.

This is a low-level function for creating conda packages without a recipe. Use this when you have files staged and want to package them directly.

Parameters:

Name Type Description Default
name str

Package name.

 required
version str

Package version.

 required
target_platform str

Target platform (e.g., "linux-64", "osx-arm64", "noarch").

 required
build_string str

Build string (e.g., "py312_0", "h1234567_0").

 required
output_dir str | Path

Directory where the package will be created.

 required
files_dir str | Path | None

Directory containing files to include. All files in this directory will be added to the package.

 None
files Sequence[FileEntry] | None

List of FileEntry objects for explicit file mappings. Use this for fine-grained control over which files to include.

 None
homepage str | None

Homepage URL for the package.

 None
license str | None

License identifier (e.g., "MIT", "Apache-2.0").

 None
license_family str | None

License family (e.g., "MIT", "GPL").

 None
summary str | None

Short one-line summary of the package.

 None
description str | None

Full description of the package.

 None
depends Sequence[str] | None

List of runtime dependencies (e.g., ["python >=3.8", "numpy"]).

 None
constrains Sequence[str] | None

List of version constraints (e.g., ["cudatoolkit >=11.0"]).

 None
build_number int

Build number (default: 0).

 0
noarch Literal['python', 'generic'] | None

Noarch type ("python" or "generic") or None for arch-specific.

 None
license_files Sequence[str | Path] | None

List of paths to license files to include.

 None
test_files Sequence[str | Path] | None

List of paths to test files to include.

 None
recipe_dir str | Path | None

Path to recipe directory to include in info/recipe/.

 None
compression_level int

Compression level 0-9 (default: 9, higher = smaller but slower).

 9
archive_type ArchiveType

Archive format (default: ArchiveType.Conda).

 Conda
timestamp datetime | None

Build timestamp as a datetime object for reproducible builds.

 None
compression_threads int | None

Number of threads for compression (default: auto-detect).

 None
detect_prefix bool

Whether to detect and record prefix placeholders (default: True).

 True

Returns:

Type Description
PackageOutput

PackageOutput with path to the created package and identifier.

Raises:

Type Description
RattlerBuildError

If package name, version, or platform is invalid, or if the build fails.
Example 
from rattler_build import assemble_package, ArchiveType

# Simple package
output = assemble_package(
    name="mypackage",
    version="1.0.0",
    target_platform="linux-64",
    build_string="py312_0",
    output_dir="/output",
    files_dir="/staged/files",
)

# Package with metadata
output = assemble_package(
    name="mypackage",
    version="1.0.0",
    target_platform="linux-64",
    build_string="py312_0",
    output_dir="/output",
    files_dir="/staged/files",
    homepage="https://github.com/org/mypackage",
    license="MIT",
    summary="My awesome package",
    depends=["python >=3.12", "numpy"],
)

collect_files#

Collect files from a directory using glob patterns.

Parameters:

Name Type Description Default
source_dir str | Path

Directory to scan for files.

 required
include_globs Sequence[str] | None

Glob patterns to include (e.g., ["/.py", "bin/"]). If not specified, all files are included by default.

 None
exclude_globs Sequence[str] | None

Glob patterns to exclude. Exclusions take precedence over inclusions.

 None
follow_symlinks bool

Whether to follow symlinks when traversing (default: False).

 False
include_hidden bool

Whether to include hidden files starting with . (default: False).

 False

Returns:

Type Description
list[FileEntry]

List of FileEntry objects for all matched files.
Example 
from rattler_build import collect_files

# Collect all Python files except tests
files = collect_files(
    "/path/to/project",
    include_globs=["**/*.py"],
    exclude_globs=["**/test_*.py", "**/__pycache__/**"],
)

# Collect everything including hidden files
files = collect_files("/path/to/project", include_hidden=True)

ArchiveType#

Bases: IntEnum

Archive type for conda packages.

TarBz2 class-attribute instance-attribute #

TarBz2 = 0

Legacy .tar.bz2 format.

Conda class-attribute instance-attribute #

Conda = 1

Modern .conda format (default, recommended).

extension #

extension()

Get the file extension for this archive type.

FileEntry#

Represents a file to be included in the package.

Attributes:

Name Type Description
source Path

Source path on disk.
destination Path

Destination path within the package (relative).
is_symlink bool

Whether this is a symlink.
symlink_target Path | None

Symlink target (if this is a symlink).

source property #

source

Source path on disk.

destination property #

destination

Destination path within the package.

is_symlink

Whether this is a symlink.

symlink_target

Symlink target (if this is a symlink).

from_paths classmethod #

from_paths(source, destination)

Create a FileEntry from source and destination paths.

Parameters:

Name Type Description Default
source str | Path

Source path on disk.

 required
destination str | Path

Destination path within the package (relative).

 required

Returns:

Type Description
FileEntry

A new FileEntry instance.

PackageOutput#

Result of successful package creation.

Attributes:

Name Type Description
path Path

Path to the created package file.
identifier str

Package identifier (name-version-build).

path property #

path

Path to the created package file.

identifier property #

identifier

Package identifier (name-version-build).