/usr/lib/python2.7/dist-packages/sage/dynamics/ is in sagemath-common 8.1-7ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python2.7/dist-packages/sage/dynamics/__init__.py
/usr/lib/python2.7/dist-packages/sage/dynamics/all.py
/usr/lib/python2.7/dist-packages/sage/dynamics/arithmetic_dynamics/
/usr/lib/python2.7/dist-packages/sage/dynamics/arithmetic_dynamics/__init__.py
/usr/lib/python2.7/dist-packages/sage/dynamics/arithmetic_dynamics/affine_ds.py
/usr/lib/python2.7/dist-packages/sage/dynamics/arithmetic_dynamics/all.py
/usr/lib/python2.7/dist-packages/sage/dynamics/arithmetic_dynamics/endPN_automorphism_group.py
/usr/lib/python2.7/dist-packages/sage/dynamics/arithmetic_dynamics/endPN_minimal_model.py
/usr/lib/python2.7/dist-packages/sage/dynamics/arithmetic_dynamics/generic_ds.py
/usr/lib/python2.7/dist-packages/sage/dynamics/arithmetic_dynamics/product_projective_ds.py
/usr/lib/python2.7/dist-packages/sage/dynamics/arithmetic_dynamics/projective_ds.py
/usr/lib/python2.7/dist-packages/sage/dynamics/arithmetic_dynamics/wehlerK3.py
/usr/lib/python2.7/dist-packages/sage/dynamics/complex_dynamics/
/usr/lib/python2.7/dist-packages/sage/dynamics/complex_dynamics/__init__.py
/usr/lib/python2.7/dist-packages/sage/dynamics/complex_dynamics/all.py
/usr/lib/python2.7/dist-packages/sage/dynamics/complex_dynamics/mandel_julia.py
/usr/lib/python2.7/dist-packages/sage/dynamics/flat_surfaces/
/usr/lib/python2.7/dist-packages/sage/dynamics/flat_surfaces/__init__.py
/usr/lib/python2.7/dist-packages/sage/dynamics/flat_surfaces/all.py
/usr/lib/python2.7/dist-packages/sage/dynamics/flat_surfaces/quadratic_strata.py
/usr/lib/python2.7/dist-packages/sage/dynamics/flat_surfaces/strata.py
/usr/lib/python2.7/dist-packages/sage/dynamics/interval_exchanges/
/usr/lib/python2.7/dist-packages/sage/dynamics/interval_exchanges/__init__.py
/usr/lib/python2.7/dist-packages/sage/dynamics/interval_exchanges/all.py
/usr/lib/python2.7/dist-packages/sage/dynamics/interval_exchanges/constructors.py
/usr/lib/python2.7/dist-packages/sage/dynamics/interval_exchanges/iet.py
/usr/lib/python2.7/dist-packages/sage/dynamics/interval_exchanges/labelled.py
/usr/lib/python2.7/dist-packages/sage/dynamics/interval_exchanges/reduced.py
/usr/lib/python2.7/dist-packages/sage/dynamics/interval_exchanges/template.py