old_contents: from sympy.core import Lambda, S, symbols
  from sympy.functions import adjoint, conjugate, transpose
  from sympy.matrices import eye, Matrix, ShapeError
  from sympy.matrices.expressions import (
      Adjoint, Identity, FunctionMatrix, MatrixExpr, MatrixSymbol, Determinant,
      det, ZeroMatrix
  )
  from sympy.utilities.pytest import raises
  
  n = symbols('n', integer=True)
  A = MatrixSymbol('A', n, n)
  B = MatrixSymbol('B', n, n)
  C = MatrixSymbol('C', 3, 4)
  
  
  def test_det():
      assert isinstance(Determinant(A), Determinant)
      assert not isinstance(Determinant(A), MatrixExpr)
      raises(ShapeError, lambda: Determinant(C))
      print det(eye(3))
      assert det(eye(3)) == 1
      assert det(Matrix(3, 3, [1, 3, 2, 4, 1, 3, 2, 5, 2])) == 17
      A / det(A)  # Make sure this is possible
  
      raises(TypeError, lambda: Determinant(S.One))
  
      assert Determinant(A).arg is A
  
new_contents: from sympy.core import Lambda, S, symbols
  from sympy.functions import adjoint, conjugate, transpose
  from sympy.matrices import eye, Matrix, ShapeError
  from sympy.matrices.expressions import (
      Adjoint, Identity, FunctionMatrix, MatrixExpr, MatrixSymbol, Determinant,
      det, ZeroMatrix
  )
  from sympy.utilities.pytest import raises
  
  n = symbols('n', integer=True)
  A = MatrixSymbol('A', n, n)
  B = MatrixSymbol('B', n, n)
  C = MatrixSymbol('C', 3, 4)
  
  
  def test_det():
      assert isinstance(Determinant(A), Determinant)
      assert not isinstance(Determinant(A), MatrixExpr)
      raises(ShapeError, lambda: Determinant(C))
      assert det(eye(3)) == 1
      assert det(Matrix(3, 3, [1, 3, 2, 4, 1, 3, 2, 5, 2])) == 17
      A / det(A)  # Make sure this is possible
  
      raises(TypeError, lambda: Determinant(S.One))
  
      assert Determinant(A).arg is A
  
subject: remove errant print statement