Update installation method

Try to update to use more-recent Python packaging code. It is
limited by Sherpa (in that I'm not trying to support newer
setuptools version than Sherpa, at least for the time being, even
if we can do here).

README.rst

@@ -40,8 +40,7 @@ with XSPEC support
 The following Python packages are required:
 
 - sherpa
-- `Astropy <http://www.astropy.org/>`_ (restricted to version 3.0 when
-  using CIAO 4.11)
+- `Astropy <http://www.astropy.org/>`_
 - `SciPy <https://www.scipy.org/scipylib/>`_.
 
 Installation
@@ -52,13 +51,13 @@ you should be able to install ``deproject`` with the command::
 
   pip3 install deproject
 
-For CIAO 4.11, please use the slightly-more involved::
+The installation requires pip version 19 or higher, but as that
+was released in early 2019 it should be available.
 
-  echo "numpy==1.12.1" > constraints.txt
-  pip3 install -c constraints.txt 'astropy<3.1' deproject scipy
-
-which avoids updating NumPy (as this is an untested combination
-with this build).
+The `installation documentation
+<https://deproject.readthedocs.io/installation.html>`_ describes how
+to build a development version from the `GitHub repository
+<https://github.com/sherpa-deprojcet/deproject>`_.
 
 Example
 -------

docs/changes.rst

@@ -5,6 +5,15 @@
 Changes
 *******
 
+.. _changes_021:
+
+Version 0.2.1
+=============
+
+The build system has been updated to use ``pip`` rather than
+``setup.py``. Please report any problems on the
+`issues page <https://github.com/sherpa-deproject/deproject/issues/>`_.
+
 .. _changes_020:
 
 Version 0.2.0

docs/conf.py

@@ -59,7 +59,7 @@
 
 # General information about the project.
 project = u'deproject'
-copyright = u'2009, 2019, 2020, 2021 Tom Aldcroft'
+copyright = u'2009, 2019, 2020, 2021, 2022 Tom Aldcroft'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the

docs/installation.rst

@@ -4,17 +4,15 @@
 Installation
 ============
 
-As of :ref:`version 0.2.0 <changes_020>`,
-the :mod:`deproject` package can be installed
-directly from `PyPI`_. This requires
-`CIAO 4.11 <http://cxc.harvard.edu/ciao/>`_
-or later (as installation with pip in earlier versions of
-CIAO is not well supported). The module *can* be used with the
-`standalone release of
-Sherpa <https://sherpa.readthedocs.io/en/latest/ciao.html>`_,
-but it is only useful if Sherpa has been built with
-`XSPEC support <https://sherpa.readthedocs.io/en/latest/install.html#xspec>`_
-which is trickier to achieve than we would like.
+As of :ref:`version 0.2.0 <changes_020>`, the :mod:`deproject` package
+can be installed directly from `PyPI`_. This requires `CIAO 4.11
+<http://cxc.harvard.edu/ciao/>`_ or later (in general the latest
+release of CIAO should be used). The module *can* be used with the
+`standalone release of Sherpa
+<https://sherpa.readthedocs.io/en/latest/ciao.html>`_, but it is only
+useful if Sherpa has been built with `XSPEC support
+<https://sherpa.readthedocs.io/en/latest/install.html#xspec>`_ which
+is trickier to achieve than we would like.
 
 Requirements
 ------------
@@ -23,9 +21,9 @@ The package uses `Astropy`_ and `SciPy`_, for units support and
 cosmological-distance calculations. It is assumed that
 `Matplotlib`_ is available for plotting.
 
-Installation is easier with CIAO 4.12 than CIAO 4.11 since
-CIAO 4.12 is available via conda (so there is less need to
-use a constraints file).
+It is **strongly** advised to use the latest CIAO (at the time
+of writing this is CIAO 4.14) installed with conda. Support
+for CIAO installed via the ciao-install script is limited.
 
 Using pip
 ---------
@@ -39,16 +37,6 @@ depends on whether CIAO was installed via `ciao-install` or
 This approach should also work if you are using the standalone
 version of Sherpa.
 
-If you are using CIAO 4.11 then you should install `deproject`
-with the following::
-
-  echo "numpy==1.12.1" > constraints.txt
-  pip install -c constraints.txt 'astropy<3.1' deproject
-
-.. note::
-   The Astropy restriction is because version 3.1 requires NumPy version
-   1.13 or later but CIAO 4.11 is shipped with NumPy version 1.12.
-
 Manual installation
 -------------------
 
@@ -61,7 +49,7 @@ by cloning the repository) and moving into the directory
 (`deproject-<version>` or `deproject`), installation just
 requires::
 
-  python setup.py install
+  pip install .
 
 .. note::
    This command should only be run after setting up CIAO or whatever
@@ -71,18 +59,12 @@ Test
 ----
 
 The source installation includes a basic test suite, which can be
-run with either
+run with
 
 ::
    
   pytest
 
-or
-
-::
-   
-  python setup.py test
-
 Example data
 ------------
 

pyproject.toml

@@ -0,0 +1,5 @@
+[build-system]
+requires = ["setuptools >= 51.0.0, < 60",  # follow Sherpa
+            "wheel"
+            ]
+build-backend = "setuptools.build_meta"

readthedocs.yml

@@ -9,6 +9,6 @@ conda:
   environment: rtd-environment.yml
 
 python:
-   version: 3.7
+   version: 3.8
    # setup_py_install: true
    # use_system_site_packages: true

rtd-environment.yml

@@ -5,7 +5,7 @@ channels:
   - sherpa
 
 dependencies:
-  - python=3.7
+  - python=3.8
   - numpy
   - sherpa
   - astropy

setup.cfg

@@ -1,5 +1,46 @@
-[aliases]
-test=pytest
+[metadata]
+version = 0.2.1
+name = deproject
+author = Douglas Burke, Tom Aldcroft
+author_email = [email protected]
+url = https://deproject.readthedocs.io/
+project_urls =
+    Issue Tracker = https://github.com/sherpa-deproject/deproject/issues/
+    Source Code = https://github.com/sherpa-deproject/deproject/
+    Documentaion = https://deproject.readthedocs.io/
 
-[build_sphinx]
-source-dir = docs
+keywords = deprojection, xray, 3d, 2d, plasma, Astrophysics, onion
+
+description = Sherpa deprojection package (X-ray analysis of Galaxy Clusters, Groups, and Galaxies)
+long_description = file: README.rst
+long_description_content_type = text/x-rst
+license = BSD
+license_files = LICENSE
+platforms = Linux, Mac OS X
+classifiers =
+    Development Status :: 4 - Beta
+    Intended Audience :: Science/Research
+    License :: OSI Approved :: BSD License
+    Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.9
+    Topic :: Scientific/Engineering :: Astronomy
+    Topic :: Scientific/Engineering :: Physics
+
+[options]
+# zip_safe = False
+python_requires = ~=3.7
+install_requires =
+    sherpa
+    astropy
+    scipy
+
+tests_require =
+    pytest
+
+package_dir =
+    =src
+packages = find:
+
+[options.packages.find]
+where=src

setup.py

@@ -1,45 +1,3 @@
-from setuptools import setup, find_packages
-
-with open('README.rst', 'rt') as fh:
-    long_description = fh.read()
-
-setup(name='deproject',
-      version='0.2.1',
-      license='BSD',
-      description='Sherpa deprojection package (X-ray analysis of Galaxy Clusters, Groups, and Galaxies)',
-      keywords='deprojection xray 3d 2d plasma Astrophysics onion',
-      long_description=long_description,
-      long_description_content_type='text/x-rst',
-      author='Douglas Burke, Tom Aldcroft',
-      author_email='[email protected]',
-
-      url='https://deproject.readthedocs.io/',
-      project_urls={
-          'Documentation': 'https://deproject.readthedocs.io/',
-          'Source Code': 'https://github.com/sherpa-deproject/deproject/',
-          'Issues': 'https://github.com/sherpa-deproject/deproject/issues/',
-          },
-
-      packages=find_packages('src'),
-      package_dir={'': 'src'},
-
-      setup_requires=['pytest-runner'],
-      tests_require=['pytest'],
-      install_requires=['sherpa', 'astropy', 'scipy'],
-
-      python_requires='~=3.5',
-
-      classifiers=[
-          'Development Status :: 4 - Beta',
-          'Intended Audience :: Science/Research',
-          'License :: OSI Approved :: BSD License',
-          'Programming Language :: Python :: 3.5',
-          'Programming Language :: Python :: 3.6',
-          'Programming Language :: Python :: 3.7',
-          'Topic :: Scientific/Engineering :: Astronomy',
-          'Topic :: Scientific/Engineering :: Physics'
-          ],
-
-      # I think this should be zip_safe, but have not tried it
-      # zip_safe=False
-      )
+# This is needed to allow setuptools to handle efitable mode
+from setuptools import setup
+setup()