I also visited official docs but same syntax is given. Here's my code.
df = pd.DataFrame({'team': ['A', 'B', 'C', 'D'],
'points': [88, 91, 99, 94],
'assists': [12, 17, 24, 28],
'rebounds': [22, 28, 30, 31]})
pd.melt(df, id_vars = ['team'], value_vars = ['points','assists'])
df