RF: let setuptools do some dependency checking

matthew-brett · matthew-brett · commit f9cc17944920 · 2015-10-17T12:41:08.000-07:00
Let setuptools do dependency checking when packages are not installed,
or they are easy to install.
diff --git a/setup.py b/setup.py
@@ -11,15 +11,9 @@
 # update it when the contents of directories change.
 if exists('MANIFEST'): os.remove('MANIFEST')
 
-# Import build helpers
-try:
-    from nisext.sexts import package_check
-except ImportError:
-    raise RuntimeError('Need nisext package from nibabel installation'
-                       ' - please install nibabel first')
-
 from setup_helpers import (generate_a_pyrex_source, get_comrec_build,
-                           cmdclass, INFO_VARS)
+                           cmdclass, INFO_VARS, get_pkg_version,
+                           version_error_msg)
 
 # monkey-patch numpy distutils to use Cython instead of Pyrex
 from numpy.distutils.command.build_src import build_src
@@ -60,42 +54,28 @@ def configuration(parent_package='',top_path=None):
 if not 'extra_setuptools_args' in globals():
     extra_setuptools_args = dict()
 
-
 # Hard and soft dependency checking
-package_check('numpy', INFO_VARS['NUMPY_MIN_VERSION'])
-package_check('scipy', INFO_VARS['SCIPY_MIN_VERSION'])
-package_check('nibabel', INFO_VARS['NIBABEL_MIN_VERSION'])
-package_check('sympy', INFO_VARS['SYMPY_MIN_VERSION'])
-def _mayavi_version(pkg_name):
-    """Mayavi2 pruned enthought. namespace at 4.0.0
-    """
-    v = ''
-    try:
-        from mayavi import version
-        v = version.version
-        if v == '':
-            v = '4.0.0' # must be the one in Debian
-    except ImportError:
-        from enthought.mayavi import version
-        v = version.version
-    return v
-package_check('mayavi',
-              INFO_VARS['MAYAVI_MIN_VERSION'],
-              optional=True,
-              version_getter=_mayavi_version)
-# Cython can be a build dependency
-def _cython_version(pkg_name):
-    from Cython.Compiler.Version import version
-    return version
-package_check('cython',
-              INFO_VARS['CYTHON_MIN_VERSION'],
-              optional=True,
-              version_getter=_cython_version,
-              messages={'opt suffix': ' - you will not be able '
-                        'to rebuild Cython source files into C files',
-                        'missing opt': 'Missing optional build-time '
-                        'package "%s"'}
-              )
+DEPS = (
+    ('numpy', INFO_VARS['NUMPY_MIN_VERSION'], 'setup_requires', True),
+    ('scipy', INFO_VARS['SCIPY_MIN_VERSION'], 'install_requires', True),
+    ('nibabel', INFO_VARS['NIBABEL_MIN_VERSION'], 'install_requires', False),
+    ('sympy', INFO_VARS['SYMPY_MIN_VERSION'], 'install_requires', False))
+
+using_setuptools = 'setuptools' in sys.modules
+
+for name, min_ver, req_type, heavy in DEPS:
+    found_ver = get_pkg_version(name)
+    ver_err_msg = version_error_msg(name, found_ver, min_ver)
+    if not using_setuptools:
+        if ver_err_msg != None:
+            raise RuntimeError(ver_err_msg)
+    else:  # Using setuptools
+        # Add packages to given section of setup/install_requires
+        if ver_err_msg != None or not heavy:
+            new_req = '{0}>={1}'.format(name, min_ver)
+            old_reqs = extra_setuptools_args.get(req_type, [])
+            extra_setuptools_args[req_type] = old_reqs + [new_req]
+
 
 ################################################################################
 # commands for installing the data
diff --git a/setup_helpers.py b/setup_helpers.py
@@ -372,6 +372,39 @@ def run(self):
     return MyBuildPy
 
 
+def get_pkg_version(pkg_name):
+    """ Return package version for `pkg_name` if installed
+
+    Returns
+    -------
+    pkg_version : str or None
+        Return None if package not importable.  Return 'unknown' if standard
+        ``__version__`` string not present. Otherwise return version string.
+    """
+    try:
+        pkg = __import__(pkg_name)
+    except ImportError:
+        return None
+    try:
+        return pkg.__version__
+    except AttributeError:
+        return 'unknown'
+
+
+def version_error_msg(pkg_name, found_ver, min_ver):
+    """ Return informative error message for version or None
+    """
+    if found_ver is None:
+        return 'We need package {0}, but not importable'.format(pkg_name)
+    if found_ver == 'unknown':
+        msg = 'We need {0} version {1}, but cannot get version'.format(
+            pkg_name, min_ver)
+    if LooseVersion(found_ver) >= LooseVersion(min_ver):
+        return None
+    return 'We need {0} version {1}, but found version {2}'.format(
+        pkg_name, found_ver, min_ver)
+
+
 # The command classes for distutils, used by setup.py
 cmdclass = {'api_docs': APIDocs,
             'clean': Clean,
