如果Fruit列中的所有值总是只有Apple或Strawberry您可以比较每组的集合，然后通过 True 的值的 sum 计算 ID:

If always all values are only Apple or Strawberry in column Fruit you can compare sets per groups and then count ID by sum of Trues values:

v = ['Apple','Strawberry']
out = df.groupby('ID')['Fruit'].apply(lambda x: set(x) == set(v)).sum()
print (out)
2

如果有很多值:

s = df.groupby('ID')['Fruit'].agg(frozenset).value_counts()
print (s)
{Apple}                2
{Strawberry, Apple}    2
{Strawberry}           1
Name: Fruit, dtype: int64