/usr/lib/python2.7/dist-packages/sage/modules/ is in sagemath-common 8.1-7ubuntu1.
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..
/usr/lib/python2.7/dist-packages/sage/modules/__init__.py
/usr/lib/python2.7/dist-packages/sage/modules/all.py
/usr/lib/python2.7/dist-packages/sage/modules/complex_double_vector.py
/usr/lib/python2.7/dist-packages/sage/modules/diamond_cutting.py
/usr/lib/python2.7/dist-packages/sage/modules/fg_pid/
/usr/lib/python2.7/dist-packages/sage/modules/fg_pid/__init__.py
/usr/lib/python2.7/dist-packages/sage/modules/fg_pid/fgp_element.py
/usr/lib/python2.7/dist-packages/sage/modules/fg_pid/fgp_module.py
/usr/lib/python2.7/dist-packages/sage/modules/fg_pid/fgp_morphism.py
/usr/lib/python2.7/dist-packages/sage/modules/filtered_vector_space.py
/usr/lib/python2.7/dist-packages/sage/modules/finite_submodule_iter.pxd
/usr/lib/python2.7/dist-packages/sage/modules/free_module.py
/usr/lib/python2.7/dist-packages/sage/modules/free_module_element.pxd
/usr/lib/python2.7/dist-packages/sage/modules/free_module_homspace.py
/usr/lib/python2.7/dist-packages/sage/modules/free_module_integer.py
/usr/lib/python2.7/dist-packages/sage/modules/free_module_morphism.py
/usr/lib/python2.7/dist-packages/sage/modules/free_quadratic_module.py
/usr/lib/python2.7/dist-packages/sage/modules/free_quadratic_module_integer_symmetric.py
/usr/lib/python2.7/dist-packages/sage/modules/matrix_morphism.py
/usr/lib/python2.7/dist-packages/sage/modules/misc.py
/usr/lib/python2.7/dist-packages/sage/modules/module.pxd
/usr/lib/python2.7/dist-packages/sage/modules/module_functors.py
/usr/lib/python2.7/dist-packages/sage/modules/multi_filtered_vector_space.py
/usr/lib/python2.7/dist-packages/sage/modules/quotient_module.py
/usr/lib/python2.7/dist-packages/sage/modules/real_double_vector.py
/usr/lib/python2.7/dist-packages/sage/modules/tensor_operations.py
/usr/lib/python2.7/dist-packages/sage/modules/tutorial_free_modules.py
/usr/lib/python2.7/dist-packages/sage/modules/vector_callable_symbolic_dense.py
/usr/lib/python2.7/dist-packages/sage/modules/vector_complex_double_dense.pxd
/usr/lib/python2.7/dist-packages/sage/modules/vector_double_dense.pxd
/usr/lib/python2.7/dist-packages/sage/modules/vector_integer_dense.pxd
/usr/lib/python2.7/dist-packages/sage/modules/vector_integer_sparse.pxd
/usr/lib/python2.7/dist-packages/sage/modules/vector_mod2_dense.pxd
/usr/lib/python2.7/dist-packages/sage/modules/vector_modn_dense.pxd
/usr/lib/python2.7/dist-packages/sage/modules/vector_modn_sparse.pxd
/usr/lib/python2.7/dist-packages/sage/modules/vector_rational_dense.pxd
/usr/lib/python2.7/dist-packages/sage/modules/vector_rational_sparse.pxd
/usr/lib/python2.7/dist-packages/sage/modules/vector_real_double_dense.pxd
/usr/lib/python2.7/dist-packages/sage/modules/vector_space_homspace.py
/usr/lib/python2.7/dist-packages/sage/modules/vector_space_morphism.py
/usr/lib/python2.7/dist-packages/sage/modules/vector_symbolic_dense.py
/usr/lib/python2.7/dist-packages/sage/modules/with_basis/
/usr/lib/python2.7/dist-packages/sage/modules/with_basis/__init__.py
/usr/lib/python2.7/dist-packages/sage/modules/with_basis/indexed_element.pxd
/usr/lib/python2.7/dist-packages/sage/modules/with_basis/morphism.py
/usr/lib/python2.7/dist-packages/sage/modules/with_basis/representation.py
/usr/lib/python2.7/dist-packages/sage/modules/with_basis/subquotient.py