path
A list of strings that specifies the search path for modules. Initialized from the environment variable PYTHONPATH, plus an installation-dependent default.
As initialized upon program startup, the first item of this
list, path[0], is the directory containing the script
that was used to invoke the Python interpreter. If the script
directory is not available (e.g. if the interpreter is invoked
interactively or if the script is read from standard input),
path[0] is the empty string, which directs Python to search
modules in the current directory first. Notice that the script
directory is inserted before the entries inserted as a
result of PYTHONPATH.
A program is free to modify this list for its own purposes.
Changed in version 2.3: Unicode strings are no longer ignored.