Basic dependency checking. setup() has two new optional arguments
requires and provides. requires is a sequence of strings, of the
form 'packagename-version'. The dependency checking so far merely
does an '__import__(packagename)' and checks for packagename.__version__
You can also leave off the version, and any version of the package
will be installed.
There's a special case for the package 'python' - sys.version_info
is used, so
requires= ( 'python-2.3', )
just works.
Provides is of the same format as requires - but if it's not supplied,
a provides is generated by adding the version to each entry in packages,
or modules if packages isn't there.
Provides is currently only used in the PKG-INFO file. Shortly, PyPI
will grow the ability to accept these lines, and register will be
updated to send them.
There's a new command 'checkdep' command that runs these checks.
For this version, only greater-than-or-equal checking is done. We'll
add the ability to specify an optional operator later.
diff --git a/Lib/distutils/command/checkdep.py b/Lib/distutils/command/checkdep.py
new file mode 100644
index 0000000..729002c
--- /dev/null
+++ b/Lib/distutils/command/checkdep.py
@@ -0,0 +1,70 @@
+"""distutils.command.x
+
+Implements the Distutils 'x' command.
+"""
+
+# created 2000/mm/dd, John Doe
+
+__revision__ = "$Id$"
+
+from distutils.core import Command
+
+class DependencyFailure(Exception): pass
+
+class VersionTooOld(DependencyFailure): pass
+
+class VersionNotKnown(DependencyFailure): pass
+
+class checkdep (Command):
+
+ # Brief (40-50 characters) description of the command
+ description = "check package dependencies"
+
+ # List of option tuples: long name, short name (None if no short
+ # name), and help string.
+ # Later on, we might have auto-fetch and the like here. Feel free.
+ user_options = []
+
+ def initialize_options (self):
+ self.debug = None
+
+ # initialize_options()
+
+
+ def finalize_options (self):
+ pass
+ # finalize_options()
+
+
+ def run (self):
+ from distutils.version import LooseVersion
+ failed = []
+ for pkg, ver in self.distribution.metadata.requires:
+ if pkg == 'python':
+ if ver is not None:
+ # Special case the 'python' package
+ import sys
+ thisver = LooseVersion('%d.%d.%d'%sys.version_info[:3])
+ if thisver < ver:
+ failed.append(((pkg,ver), VersionTooOld(thisver)))
+ continue
+ # Kinda hacky - we should do more here
+ try:
+ mod = __import__(pkg)
+ except Exception, e:
+ failed.append(((pkg,ver), e))
+ continue
+ if ver is not None:
+ if hasattr(mod, '__version__'):
+ thisver = LooseVersion(mod.__version__)
+ if thisver < ver:
+ failed.append(((pkg,ver), VersionTooOld(thisver)))
+ else:
+ failed.append(((pkg,ver), VersionNotKnown()))
+
+ if failed:
+ raise DependencyFailure, failed
+
+ # run()
+
+# class x