一种方法是先转换为元组.这是因为 pandas.groupby 要求键是可散列的.元组是不可变和可散列的，但列表不是.

One way is to convert to tuples first. This is because pandas.groupby requires keys to be hashable. Tuples are immutable and hashable, but lists are not.

res = df.groupby(df['List'].map(tuple))['Count'].sum()

结果:

List
(a, time)       6
(once, upon)    5
(there, was)    1
Name: Count, dtype: int64

如果您需要数据帧中的列表形式的结果，您可以转换回来:

If you need the result as lists in a dataframe, you can convert back:

res = df.groupby(df['List'].map(tuple))['Count'].sum()
res['List'] = res['List'].map(list)

#            List  Count
# 0     [a, time]      6
# 1  [once, upon]      5
# 2  [there, was]      1