[SciPy-User] how to get the indexes of non zero rows of sparse matric efficiently when using scipy?

[teccy]

for example, a 500x1000 sparse matrix with 300 non zero rows and 5000 non zero items, what i want is the index for the 300 rows, not the index for 5000 items, how to do this efficiently, seems scipy haven't provicde such kind of API ...
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