Relative imports in python 2.5

by

Take a look at the following info from PEP 328:

Relative imports use a module’s __name__ attribute to determine that module’s position in the package hierarchy. If the module’s name does not contain any package information (e.g. it is set to '__main__') then relative imports are resolved as if the module were a top level module, regardless of where the module is actually located on the file system.

When you run foo.py as a script, that module’s __name__ is '__main__', so you cannot do relative imports. This would be true even if mypackage was on sys.path. Basically, you can only do relative imports from a module if that module was imported.

Here are a couple of options for working around this:

1) In foo.py, check if __name__ == '__main__' and conditionally add mypackage to sys.path: 

if __name__ == '__main__':
    import os, sys
    # get an absolute path to the directory that contains mypackage
    foo_dir = os.path.dirname(os.path.join(os.getcwd(), __file__))
    sys.path.append(os.path.normpath(os.path.join(foo_dir, '..', '..')))
    from mypackage import bar
else:
    from .. import bar

2) Always import bar using from mypackage import bar, and execute foo.py in such a way that mypackage is visible automatically:

$ cd <path containing mypackage>
$ python -m mypackage.foo.foo

More Related Contents:

  1. Relative imports for the billionth time
  2. Importing from a relative path in Python
  3. How to import a Python module from a sibling folder?
  4. Defined variable is not defined
  5. Import a module from a relative path
  6. What is the purpose of a backslash at the end of a line?
  7. Import module from subfolder
  8. Python: avoid new line with print command [duplicate]
  9. Python module with a dash, or hyphen (-) in its name
  10. Why might Python’s `from` form of an import statement bind a module name?
  11. How to change a module variable from another module?
  12. Do I need to import submodules directly?
  13. Read data from CSV file and transform from string to correct data-type, including a list-of-integer column
  14. Trace Python imports
  15. Difference between “import X” and “from X import *”? [duplicate]
  16. How to prevent a module from being imported twice?
  17. What does from __future__ import absolute_import actually do?
  18. ImportError: No module named – Python
  19. How to make global imports from a function?
  20. Prevent Python from caching the imported modules
  21. How to make an “always relative to current module” file path?
  22. How can I import from the standard library, when my project has a module with the same name? (How can I control where Python looks for modules?)
  23. Python, doing conditional imports the right way
  24. Tell if Python is in interactive mode
  25. Dynamically import a method in a file, from a string
  26. Why doesn’t an import in an exec in a function work?
  27. Import python module NOT on path
  28. How can I import files in Python using sys.path.append?
  29. Simple cross import in python
  30. How to reference python package when filename contains a period

Leave a Comment