class_docstr: Useful commands
  - run all tests: pytest examples/orderbook_data/example.py
  - run a single test:  pytest -s --pdb --disable-warnings examples/orderbook_data/example.py::TestClass::test_basic01
class_docstr_tok: ["Useful","commands","-","run","all","tests",":","pytest","examples\/orderbook_data\/example.py","-","run","a","single","test",":","pytest","-s","--","pdb","--","disable-warnings","examples\/orderbook_data\/example.py",":",":TestClass",":",":test_basic01"]
code: def test_exp_03(self):
      expr3_func1 = (
          lambda name, index_left, index_right: f"2 * TResample(Abs(${name}{index_left} - ${name}{index_right}), '1min', 'last') / {self.expr_sum_buy_ask_1}"
      )
      for name in ["ask", "bid"]:
          for i in range(1, 10):
              exprs = [expr3_func1(name, i + 1, i)]
              names = [f"p_diff_{name}_{i}_{i+1}"]
      exprs.extend(
          [expr3_func1("ask", 10, 1), expr3_func1("bid", 1, 10)]
      )
      names.extend(["p_diff_ask_10_1", "p_diff_bid_1_10"])
      df = D.features(self.stocks_list, fields=exprs, freq="ticks")
      df.columns = names
      print(df)
  
imports: from arctic.arctic import Arctic
  import qlib
  from qlib.data import D
  import unittest
label_desc: Use image node_id 10 for calling the TestClass obj's underlying member method code with example usage: obj.test_exp_03() without return types