Pandas pivot to sparse

from scipy.sparse import csr_matrix
from pandas.api.types import CategoricalDtype

person_c = CategoricalDtype(sorted(frame.person.unique()), ordered=True)
thing_c = CategoricalDtype(sorted(frame.thing.unique()), ordered=True)

row = frame.person.astype(person_c).cat.codes
col = frame.thing.astype(thing_c).cat.codes
sparse_matrix = csr_matrix((frame["count"], (row, col)), \
                           shape=(person_c.categories.size, thing_c.categories.size))

>>> sparse_matrix
<3x4 sparse matrix of type '<class 'numpy.int64'>'
     with 6 stored elements in Compressed Sparse Row format>

>>> sparse_matrix.todense()
matrix([[0, 1, 0, 1],
        [1, 0, 0, 1],
        [1, 0, 1, 0]], dtype=int64)


dfs = pd.SparseDataFrame(sparse_matrix, \
                         index=person_c.categories, \
                         columns=thing_c.categories, \
                         default_fill_value=0)
>>> dfs
        a   b   c   d
 him    0   1   0   1
  me    1   0   0   1
 you    1   0   1   0

Source: stackoverflow.com

Similar codes

-1 vote142 views1 answer
Rewrite the equation shown in Figure 2.4 as a Python expression and get the result of the equation: Pay special attention to the order of operations.
Python
2 votes178 views2 answers
Python program to print list vertically without using loop
Python
0 vote137 views2 answers
How to make SAPI.SpVoice say a variable in python
Python
2 votes137 views1 answer
Python method to check for uppercase character
Python
0 vote161 views1 answer
Flask decoding base 64 image
Python Flask
0 vote138 views1 answer
Contar ocorrências letra string python
Python
0 vote150 views1 answer
AttributeError: 'NoneType' object has no attribute 'dropna'
Python
0 vote137 views1 answer
Choose a random snippet of text
Python
0 vote136 views1 answer
BusyIndicator Import
Python
0 vote176 views1 answer
Python wait for executable to finish before perceeding
Python