version: Add get_versions and teach rss2email --full-version

This makes it easier for users to submit useful bug reports.

Signed-off-by: W. Trevor King <wking@tremily.us>

diff --git a/rss2email/main.py b/rss2email/main.py
index 47817fe0b996b8751b8c9cff72293f0515d3b577..3c8dc1cfb61bed82a701b87cf9f5006a571df9e2 100644 (file)
--- a/rss2email/main.py
+++ b/rss2email/main.py
@@ -11,6 +11,14 @@ from . import LOG as _LOG
 from . import command as _command
 from . import error as _error
 from . import feeds as _feeds
+from . import version as _version
+
+
+class FullVersionAction (_argparse.Action):
+    def __call__(self, *args, **kwargs):
+        for package,version in _version.get_versions():
+            print('{} {}'.format(package, version))
+        _sys.exit(0)
 
 
 def run(*args, **kwargs):
@@ -25,6 +33,9 @@ def run(*args, **kwargs):
     parser.add_argument(
         '-v', '--version', action='version',
         version='%(prog)s {}'.format(__version__))
+    parser.add_argument(
+        '--full-version', action=FullVersionAction, nargs=0,
+        help='print the version information of all related packages and exit')
     parser.add_argument(
         '-c', '--config', metavar='PATH', default=[], action='append',
         help='path to the configuration file')

diff --git a/rss2email/version.py b/rss2email/version.py
new file mode 100644 (file)
index 0000000..65e8b5d
--- /dev/null
+++ b/rss2email/version.py
@@ -0,0 +1,35 @@
+# Copyright
+
+"""Calculate version numbers for this package and its dependencies
+
+This makes it easier for users to submit useful bug reports.
+"""
+
+import importlib as _importlib
+import sys as _sys
+
+from . import __version__
+
+
+def get_rss2email_version(package):
+    return __version__
+
+def get_python_version(package):
+    return _sys.version
+
+def get_python_package_version(package):
+    try:
+        module = _importlib.import_module(package)
+    except ImportError as e:
+        return None
+    return getattr(module, '__version__', 'unknown')
+
+def get_versions(packages=None):
+    if not packages:
+        packages = ['rss2email', 'python', 'feedparser', 'html2text']
+    for package in packages:
+        get = globals().get(
+            'get_{}_version'.format(package),
+            get_python_package_version)
+        version = get(package=package)
+        yield (package, version)