def adata():
    adata = ad.AnnData(np.zeros((100, 100)))
    adata.obsm["o"] = np.zeros((100, 50))
    adata.varm["o"] = np.zeros((100, 50))
    return adata
def allowed_file(filename):
    return '.' in filename and \
           filename.rsplit('.', 1)[1] in app.config.get('ALLOWED_EXTENSIONS')