use*_*009 4 python sparse-matrix dataframe pandas
sdf = df.to_sparse()已被弃用。转换为稀疏 DataFrame 的更新方法是什么?
这些是pandas 1.0.0+ 中更新的稀疏转换。
DataFrame.astype()与适当的SparseDtype()(例如, )一起使用int:
>>> df = pd.DataFrame({'A': [1, 0, 0, 0, 1, 0]})
>>> df.dtypes
# A int64
# dtype: object
>>> sdf = df.astype(pd.SparseDtype(int, fill_value=0))
>>> sdf.dtypes
# A Sparse[int64, 0]
# dtype: object
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或者为了简洁起见使用字符串别名:
>>> sdf = df.astype('Sparse[int64, 0]')
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使用DataFrame.sparse.to_dense():
>>> sdf = df.astype('Sparse[int64, 0]')
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>>> from scipy import sparse
>>> sdf = pd.DataFrame.sparse.from_spmatrix(sparse.eye(3), columns=list('ABC'))
>>> sdf.dtypes
# A Sparse[float64, 0]
# B Sparse[float64, 0]
# C Sparse[float64, 0]
# dtype: object
>>> df = sdf.sparse.to_coo()
# <3x3 sparse matrix of type '<class 'numpy.float64'>'
# with 3 stored elements in COOrdinate format>
# (0, 0) 1.0
# (1, 1) 1.0
# (2, 2) 1.0
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