How do I change the representation while storing a sparse matrix in python?

The sparse matrix representation is of the form:

          (i,j)       value

I want to store these values 开发者_JS百科to a text file in 3 columns namely:

         i            j               value

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If your sparse matrix is stored in a dictionary called dict then you can use:

f = open('output.txt', 'w')
for (i, j), value in dict.items():
    f.write("%s\t%s\t%s\n" % (i, j, value))

This will output the data as a tab-delimited text file.