diff --git a/Cargo.toml b/Cargo.toml
index 0d6dbe6f..e446f6df 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,10 +1,5 @@
 [workspace]
-members = [
-    "pineappl",
-    "pineappl_capi",
-    "pineappl_py",
-    "pineappl_cli",
-]
+members = ["pineappl", "pineappl_capi", "pineappl_cli"]
 
 [profile.release]
 lto = true
diff --git a/pineappl/.gitignore b/pineappl/.gitignore
new file mode 100644
index 00000000..bfbb67c1
--- /dev/null
+++ b/pineappl/.gitignore
@@ -0,0 +1,145 @@
+
+# Created by https://www.toptal.com/developers/gitignore/api/python
+# Edit at https://www.toptal.com/developers/gitignore?templates=python
+
+### Python ###
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+pip-wheel-metadata/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+pytestdebug.log
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+doc/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+.python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+pythonenv*
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# profiling data
+.prof
+
+# End of https://www.toptal.com/developers/gitignore/api/python
diff --git a/pineappl/Cargo.toml b/pineappl/Cargo.toml
index 35ce0d64..75508792 100644
--- a/pineappl/Cargo.toml
+++ b/pineappl/Cargo.toml
@@ -20,10 +20,18 @@ float-cmp = "0.8"
 itertools = "0.9"
 lz-fear = "0.1"
 ndarray = { features = ["serde"], version = "0.13.1" }
+pyo3 = { features = ["extension-module"], optional = true, version = "0.13.1" }
 rustc-hash = "1.1.0"
 serde = { features = ["derive"], version = "1.0" }
 thiserror = "1.0"
 
+[lib]
+name = "pineappl"
+crate-type = ["cdylib", "lib"]
+
+[features]
+python = ["pyo3"]
+
 [dev-dependencies]
 lhapdf = "0.1.8"
 rand = { default-features = false, version = "0.7" }
diff --git a/pineappl_py/dev.requirements.txt b/pineappl/dev.py.requirements.txt
similarity index 100%
rename from pineappl_py/dev.requirements.txt
rename to pineappl/dev.py.requirements.txt
diff --git a/pineappl_py/examples/import-yadism-yaml.py b/pineappl/examples/import-yadism-yaml.py
similarity index 100%
rename from pineappl_py/examples/import-yadism-yaml.py
rename to pineappl/examples/import-yadism-yaml.py
diff --git a/pineappl_py/examples/requirements.txt b/pineappl/examples/py.requirements.txt
similarity index 100%
rename from pineappl_py/examples/requirements.txt
rename to pineappl/examples/py.requirements.txt
diff --git a/pineappl_py/pineappl/__init__.py b/pineappl/pineappl/__init__.py
similarity index 100%
rename from pineappl_py/pineappl/__init__.py
rename to pineappl/pineappl/__init__.py
diff --git a/pineappl_py/pineappl/bin.py b/pineappl/pineappl/bin.py
similarity index 100%
rename from pineappl_py/pineappl/bin.py
rename to pineappl/pineappl/bin.py
diff --git a/pineappl_py/pineappl/grid.py b/pineappl/pineappl/grid.py
similarity index 100%
rename from pineappl_py/pineappl/grid.py
rename to pineappl/pineappl/grid.py
diff --git a/pineappl_py/pineappl/lagrange_subgrid.py b/pineappl/pineappl/lagrange_subgrid.py
similarity index 100%
rename from pineappl_py/pineappl/lagrange_subgrid.py
rename to pineappl/pineappl/lagrange_subgrid.py
diff --git a/pineappl_py/pineappl/lumi.py b/pineappl/pineappl/lumi.py
similarity index 100%
rename from pineappl_py/pineappl/lumi.py
rename to pineappl/pineappl/lumi.py
diff --git a/pineappl_py/pineappl/subgrid.py b/pineappl/pineappl/subgrid.py
similarity index 100%
rename from pineappl_py/pineappl/subgrid.py
rename to pineappl/pineappl/subgrid.py
diff --git a/pineappl_py/pineappl/utils.py b/pineappl/pineappl/utils.py
similarity index 100%
rename from pineappl_py/pineappl/utils.py
rename to pineappl/pineappl/utils.py
diff --git a/pineappl/src/bin.rs b/pineappl/src/bin.rs
index e4bb8111..e80eda42 100644
--- a/pineappl/src/bin.rs
+++ b/pineappl/src/bin.rs
@@ -1,5 +1,8 @@
 //! Module that contains helpers for binning observables
 
+#[cfg(feature = "python")]
+use pyo3::prelude::*;
+
 use super::convert::{f64_from_usize, usize_from_f64};
 use float_cmp::approx_eq;
 use serde::{Deserialize, Serialize};
@@ -47,6 +50,7 @@ pub enum BinRemapperNewError {
 }
 
 /// Structure for remapping bin limits.
+#[cfg_attr(feature = "python", pyclass)]
 #[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct BinRemapper {
     normalizations: Vec<f64>,
@@ -148,6 +152,7 @@ impl PartialEq<BinInfo<'_>> for BinInfo<'_> {
     }
 }
 
+#[cfg_attr(feature = "python", pymethods)]
 impl BinRemapper {
     /// Create a new `BinRemapper` object with the specified number of bins and dimensions and
     /// limits.
@@ -156,6 +161,7 @@ impl BinRemapper {
     ///
     /// Returns an error if the length of `limits` is not a multiple of the length of
     /// `normalizations`.
+    #[cfg_attr(feature = "python", new)]
     pub fn new(
         normalizations: Vec<f64>,
         limits: Vec<(f64, f64)>,
diff --git a/pineappl/src/grid.rs b/pineappl/src/grid.rs
index c85f77f2..ae676e85 100644
--- a/pineappl/src/grid.rs
+++ b/pineappl/src/grid.rs
@@ -175,6 +175,7 @@ pub enum GridSetBinRemapperError {
 
 /// Main data structure of `PineAPPL`. This structure contains a `Subgrid` for each `LumiEntry`,
 /// bin, and coupling order it was created with.
+#[cfg_attr(feature = "python", pyclass)]
 #[derive(Deserialize, Serialize)]
 pub struct Grid {
     subgrids: Array3<SubgridEnum>,
@@ -185,8 +186,10 @@ pub struct Grid {
     more_members: MoreMembers,
 }
 
+#[cfg_attr(feature = "python", pymethods)]
 impl Grid {
     /// Constructor.
+    #[cfg_attr(feature = "python", new)]
     #[must_use]
     pub fn new(
         lumi: Vec<LumiEntry>,
diff --git a/pineappl/src/lib.rs b/pineappl/src/lib.rs
index 745f2525..f816e6f0 100644
--- a/pineappl/src/lib.rs
+++ b/pineappl/src/lib.rs
@@ -13,3 +13,22 @@ pub mod lumi;
 pub mod ntuple_subgrid;
 pub mod sparse_array3;
 pub mod subgrid;
+
+/// A Python module implemented in Rust.
+/// NOTE: this name has to match the one in Cargo.toml 'lib.name'
+#[cfg(feature = "python")]
+use pyo3::prelude::*;
+
+#[cfg(feature = "python")]
+#[pymodule]
+fn pineappl(_py: Python, m: &PyModule) -> PyResult<()> {
+    m.add_class::<bin::BinRemapper>()?;
+    //m.add_class::<grid::Grid>()?;
+    //m.add_class::<grid::Order>()?;
+    //m.add_class::<lagrange_subgrid::LagrangeSubgridV2>()?;
+    //m.add_class::<lumi::LumiEntry>()?;
+    //m.add_class::<subgrid::ExtraSubgridParams>()?;
+    //m.add_class::<subgrid::SubgridParams>()?;
+
+    Ok(())
+}
diff --git a/pineappl_py/tests/test_bin.py b/pineappl/tests/python/test_bin.py
similarity index 100%
rename from pineappl_py/tests/test_bin.py
rename to pineappl/tests/python/test_bin.py
diff --git a/pineappl_py/tests/test_grid.py b/pineappl/tests/python/test_grid.py
similarity index 100%
rename from pineappl_py/tests/test_grid.py
rename to pineappl/tests/python/test_grid.py
diff --git a/pineappl_py/tests/test_lagrange_subgrid.py b/pineappl/tests/python/test_lagrange_subgrid.py
similarity index 100%
rename from pineappl_py/tests/test_lagrange_subgrid.py
rename to pineappl/tests/python/test_lagrange_subgrid.py
diff --git a/pineappl_py/tests/test_lumi.py b/pineappl/tests/python/test_lumi.py
similarity index 100%
rename from pineappl_py/tests/test_lumi.py
rename to pineappl/tests/python/test_lumi.py
diff --git a/pineappl_py/tests/test_sugrid.py b/pineappl/tests/python/test_sugrid.py
similarity index 100%
rename from pineappl_py/tests/test_sugrid.py
rename to pineappl/tests/python/test_sugrid.py
diff --git a/pineappl_py/Cargo.toml b/pineappl_py/Cargo.toml
deleted file mode 100644
index be69aa34..00000000
--- a/pineappl_py/Cargo.toml
+++ /dev/null
@@ -1,23 +0,0 @@
-[package]
-name = "pineappl_py"
-version = "0.3.0"
-authors = ["Christopher Schwan <handgranaten-herbert@posteo.de>", "Alessandro Candido <candido.ale@gmail.com>"]
-edition = "2018"
-license = "GPL-3.0-or-later"
-repository = "https://github.com/N3PDF/pineappl"
-readme = "README.md"
-keywords = ["high-energy-physics", "physics"]
-categories = ["science"]
-description = "Python bindings to PineAPPL"
-
-[lib]
-name = "pineappl"
-crate-type = ["cdylib"]
-
-[dependencies]
-pineappl = { path = "../pineappl", version = "0.3.0" }
-itertools = "0.9"
-
-[dependencies.pyo3]
-version = "0.12.4"
-features = ["extension-module"]
diff --git a/pineappl_py/src/bin.rs b/pineappl_py/src/bin.rs
index 9a29e8f9..83189b6b 100644
--- a/pineappl_py/src/bin.rs
+++ b/pineappl_py/src/bin.rs
@@ -1,11 +1,8 @@
 use pineappl::bin::BinRemapper;
 
-use pyo3::prelude::*;
 //use pyo3::types::{PyList, PyTuple};
 //use pyo3::{exceptions::PyRuntimeError, Python};
 
-#[pyclass]
-#[derive(Clone)]
 #[repr(transparent)]
 pub struct PyBinRemapper {
     pub bin_remapper: BinRemapper,
diff --git a/pineappl_py/src/lib.rs b/pineappl_py/src/lib.rs
deleted file mode 100644
index eba581ce..00000000
--- a/pineappl_py/src/lib.rs
+++ /dev/null
@@ -1,22 +0,0 @@
-use pyo3::prelude::*;
-
-pub mod bin;
-pub mod grid;
-pub mod lagrange_subgrid;
-pub mod lumi;
-pub mod subgrid;
-
-/// A Python module implemented in Rust.
-/// NOTE: this name has to match the one in Cargo.toml 'lib.name'
-#[pymodule]
-fn pineappl(_py: Python, m: &PyModule) -> PyResult<()> {
-    m.add_class::<bin::PyBinRemapper>()?;
-    m.add_class::<grid::PyGrid>()?;
-    m.add_class::<grid::PyOrder>()?;
-    m.add_class::<lagrange_subgrid::PyLagrangeSubgridV2>()?;
-    m.add_class::<lumi::PyLumiEntry>()?;
-    m.add_class::<subgrid::PyExtraSubgridParams>()?;
-    m.add_class::<subgrid::PySubgridParams>()?;
-
-    Ok(())
-}