[EMAIL PROTECTED] writes: > Now when I run the 'run.py', it will print two different numbers. > sys.modules tells me that 'mod1' is imported as both 'one.mod1' and > 'mod1', which explains the result.
If I were you, I'd make sure that the module duplicate problem is resolved first, for example by putting run.py somewhere outside one/. Then the singleton problem disappears as well. > It is possible to solve this by always importing with the complete > path like 'one.mod1', even when inside the 'one' directory, but > that's an error waiting to happen. Is it, really? As far as I can tell, Python handles that case rather robustly. For example: $ mkdir one $ touch one/__init__.py $ touch one/mod1.py one/mod2.py $ echo 'import mod2' > one/mod1.py $ python Python 2.5.1 (r251:54863, May 2 2007, 16:56:35) [GCC 4.1.2 (Ubuntu 4.1.2-0ubuntu4)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import one.mod1 >>> import sys >>> sorted(sys.modules) ['UserDict', '__builtin__', '__main__', '_codecs', '_sre', '_types', 'codecs', 'copy_reg', 'encodings', 'encodings.aliases', 'encodings.codecs', 'encodings.encodings', 'encodings.types', 'encodings.utf_8', 'exceptions', 'linecache', 'one', 'one.mod1', 'one.mod2', 'os', 'os.path', 'posix', 'posixpath', 're', 'readline', 'rlcompleter', 'signal', 'site', 'sre_compile', 'sre_constants', 'sre_parse', 'stat', 'sys', 'types', 'warnings', 'zipimport'] Although mod1 imports mod2 simply with "import mod2", the fact that mod1 itself is imported as part of "one" is respected. As a result, mod2 is imported as "one.mod2", exactly as if it were imported from outside the "one" package. run.py is an exception because it is started directly using "python run.py", so it never gets the information that it's supposed to be part of a package. To fix the problem, all you need to do is make sure that executable scripts such as run.py are either placed safely outside the package, or that they take care to always use absolute imports, such as "import one.mod1" instead of "import mod1". Placing them outside the package is a good example of preventing an error waiting to happen, like the one you hinted at. -- http://mail.python.org/mailman/listinfo/python-list
