__init__.py

"""Python bindings for Drake.
"""

from __future__ import absolute_import, division, print_function
from os.path import abspath, dirname, join
from platform import python_version_tuple
from sys import stderr

import six

# When importing `pydrake` as an external under Bazel, Bazel will use a shared
# library whose relative RPATHs are incorrect for `libdrake.so`, and thus will
# fail to load; this issue is captured in bazelbuild/bazel#4594. As a
# workaround, we can use a library that properly links to `libdrake.so`, but in
# `{runfiles}/{workspace}/external/drake` rather than `{runfiles}/drake`.
# Once this is loaded, all of the Python C-extension libraries
# that depend on it (and its dependencies) will load properly.
# Please note that this workaround is only important when running under the
# Bazel runfiles tree. Installed `pydrake` should not have this issue.
# N.B. We do not import `external.drake.bindings.pydrake` as this may cause
# duplicate classes to be loaded (#8810). This will not be a problem once #7912
# is resolved.
try:
    import external.drake.bindings.bazel_workaround_4594_libdrake
except ImportError:
    pass

# When running from python, turn DRAKE_ASSERT and DRAKE_DEMAND failures into
# SystemExit, instead of process aborts.  See RobotLocomotion/drake#5268.
# We specifically load `common` prior to loading any other pydrake modules,
# in order to get assertion configuration done as early as possible.
from . import common
from .common.deprecation import ModuleShim

__all__ = ['common', 'getDrakePath']
common.set_assertion_failure_to_throw_exception()


def getDrakePath():
    # Compatibility alias.
    return abspath(common.GetDrakePath())


def _execute_extra_python_code(m):
    # See `ExecuteExtraPythonCode` in `pydrake_pybind.h` for usage details and
    # rationale.
    pydrake_dir = dirname(__file__)
    orig_pieces = m.__name__.split(".")
    assert orig_pieces[0] == __name__
    pieces = [pydrake_dir] + orig_pieces[1:-1] + [
        "_{}_extra.py".format(orig_pieces[-1])]
    filename = join(*pieces)
    if six.PY2:
        execfile(filename, m.__dict__)
    else:
        with open(filename) as f:
            _code = compile(f.read(), filename, 'exec')
            exec(_code, m.__dict__, m.__dict__)