def test_view_setattr_machinery(attr, subset_func, subset_func2):
    # Tests that setting attributes on a view doesn't mess anything up too bad
    adata = gen_adata((10, 10))
    view = adata[subset_func(adata.obs_names), subset_func2(adata.var_names)]

    actual = view.copy()
    setattr(view, attr, getattr(actual, attr))
    assert_equal(actual, view, exact=True)
def install_secret_key(app, filename='secret_key'):
    """Configure the SECRET_KEY from a file
    in the instance directory.

    If the file does not exist, print instructions
    to create it from a shell with a random key,
    then exit.
    """
    filename = os.path.join(app.instance_path, filename)

    try:
        app.config['SECRET_KEY'] = open(filename, 'rb').read()
    except IOError:
        print('Error: No secret key. Create it with:')
        full_path = os.path.dirname(filename)
        if not os.path.isdir(full_path):
            print('mkdir -p {filename}'.format(filename=full_path))
        print('head -c 24 /dev/urandom > {filename}'.format(filename=filename))
        sys.exit(1)