old_contents: """
  Window Rank Line Chart
  ----------------------
  This example shows the Group F rankings in the 2018 World Cup after each matchday. 
  A window transformation is used to rank each after each match day, sorting by points and difference.
  """
  # category: case studies
  import altair as alt
  import pandas as pd
  
  source = pd.DataFrame(
      [
          {"team": "Germany", "matchday": 1, "point": 0, "diff": -1},
          {"team": "Germany", "matchday": 2, "point": 3, "diff": 0},
          {"team": "Germany", "matchday": 3, "point": 3, "diff": -2},
          {"team": "Mexico", "matchday": 1, "point": 3, "diff": 1},
          {"team": "Mexico", "matchday": 2, "point": 6, "diff": 2},
          {"team": "Mexico", "matchday": 3, "point": 6, "diff": -1},
          {"team": "South Korea", "matchday": 1, "point": 0, "diff": -1},
          {"team": "South Korea", "matchday": 2, "point": 0, "diff": -2},
          {"team": "South Korea", "matchday": 3, "point": 3, "diff": 0},
          {"team": "Sweden", "matchday": 1, "point": 3, "diff": 1},
          {"team": "Sweden", "matchday": 2, "point": 3, "diff": 0},
          {"team": "Sweden", "matchday": 3, "point": 6, "diff": 3},
      ]
  )
  
  color_scale = alt.Scale(
      domain=["Germany", "Mexico", "South Korea", "Sweden"],
      range=["#000000", "#127153", "#C91A3C", "#0C71AB"],
  )
  
  alt.Chart(source).mark_line().encode(
      x="matchday:O", y="rank:O", color=alt.Color("team:N", scale=color_scale)
  ).transform_window(
      rank="rank()",
      sort=[
          alt.SortField("point", order="descending"),
          alt.SortField("diff", order="descending"),
      ],
      groupby=["matchday"],
  )
  
new_contents: """
  Window Rank Line Chart
  ----------------------
  This example shows the Group F rankings in the 2018 World Cup after each matchday. 
  A window transformation is used to rank each after each match day, sorting by points and difference.
  """
  # category: case studies
  import altair as alt
  import pandas as pd
  
  source = pd.DataFrame(
      [
          {"team": "Germany", "matchday": 1, "point": 0, "diff": -1},
          {"team": "Germany", "matchday": 2, "point": 3, "diff": 0},
          {"team": "Germany", "matchday": 3, "point": 3, "diff": -2},
          {"team": "Mexico", "matchday": 1, "point": 3, "diff": 1},
          {"team": "Mexico", "matchday": 2, "point": 6, "diff": 2},
          {"team": "Mexico", "matchday": 3, "point": 6, "diff": -1},
          {"team": "South Korea", "matchday": 1, "point": 0, "diff": -1},
          {"team": "South Korea", "matchday": 2, "point": 0, "diff": -2},
          {"team": "South Korea", "matchday": 3, "point": 3, "diff": 0},
          {"team": "Sweden", "matchday": 1, "point": 3, "diff": 1},
          {"team": "Sweden", "matchday": 2, "point": 3, "diff": 0},
          {"team": "Sweden", "matchday": 3, "point": 6, "diff": 3},
      ]
  )
  
  color_scale = alt.Scale(
      domain=["Germany", "Mexico", "South Korea", "Sweden"],
      range=["#000000", "#127153", "#C91A3C", "#0C71AB"],
  )
  
  alt.Chart(source).mark_line().encode(
      x="matchday:O", y="rank:O", color=alt.Color("team:N", scale=color_scale)
  ).transform_window(
      rank="rank()",
      sort=[
          alt.SortField("point", order="descending"),
          alt.SortField("diff", order="descending"),
      ],
      groupby=["matchday"],
  ).properties(title="World Cup 2018: Group F Rankings")
  
subject: add title