Python doctest example failure

This is probably a silly question.

I am experimenting with python doctest, and I try to run this example

ending with

if __name__ == "__main__":
    import doctest
    doctest.testfile("e开发者_开发知识库xample.txt")

I have put "example.txt" in the same folder as the source file containing the example code, but I get the following error:

Traceback (most recent call last):
File "test_av_funktioner.py", line 61, in <module>
doctest.testfile("example.txt")
File "C:\Python26\lib\doctest.py", line 1947, in testfile
text, filename = _load_testfile(filename, package, module_relative)
File "C:\Python26\lib\doctest.py", line 219, in _load_testfile
return open(filename).read(), filename
IOError: [Errno 2] No such file or directory: 'example.txt'

Can I somehow tell/set where the doctest module is searching for the specified file?

---

Doctest searches relative to the calling module's directory by default (but you can override this).

Quoting the docs for doctest.testfile:

Optional argument module_relative specifies how the filename should be interpreted:

• If module_relative is True (the default), then filename specifies an OS-independent module-relative path. By default, this path is relative to the calling module’s directory; but if the package argument is specified, then it is relative to that package. To ensure OS-independence, filename should use / characters to separate path segments, and may not be an absolute path (i.e., it may not begin with /).
• If module_relative is False, then filename specifies an OS-specific path. The path may be absolute or relative; relative paths are resolved with respect to the current working directory.