The only unsolved case is basic.py.

$ git grep -n ' self[ ,][^=.[!]*= '
sympy/core/basic.py:313:                self = self.base
sympy/core/expr.py:1441:        * if self is an Add then self = i + d
sympy/core/expr.py:1442:        * if self is a Mul then self = i*d
sympy/galgebra/ga.py:567:    def __add_ab__(self, b):  # self += b
sympy/galgebra/ga.py:585:    def __sub_ab__(self, b):  # self -= b
sympy/galgebra/ga.py:644:    def __mul_ab__(self, b):  # self *= b
sympy/polys/agca/modules.py:960:        # Then self = F/N.
sympy/polys/rings.py:1327:           self = sum(fv[i]*qv[i]) + r