code: def test_multiple_lines_with_weight():
      df = pd.DataFrame(
          {"y": [1, 2, -1], "w": [2.5, 1.2, 3.75], "x": ["a", "b", "c"]}
      )
      conv = DFtoVW(
          df=df,
          label=SimpleLabel(label="y", weight="w"),
          features=Feature("x"),
      )
      lines_list = conv.convert_df()
      assert lines_list == [
          "1 2.5 | x=a",
          "2 1.2 | x=b",
          "-1 3.75 | x=c",
      ]
  
imports: import pytest
  import pandas
  from vowpalwabbit.dftovw import ContextualbanditLabel, DFtoVW, Feature, MulticlassLabel, MultiLabel, Namespace, SimpleLabel
label_desc: Use image node_id 15 for calling a global function with example usage: test_multiple_lines_with_weight() without return types