source_data = {
    'wall_sign_1': {
        'x': 1118.185,
        'y': 693.035,
    },
    'wall_sign_2': {
        'x': 1258.054,
        'y': 686.978,
    },
    'D1': 51.051,
    'D2': 77.730,
    'S_t1_t2': 187.323,
    'beta_1': [79, 19, 8],
    'beta_2': [59, 57, 36],
}

x_1 = source_data['wall_sign_1']
x_1 = x_1['x']
print(x_1)