BUG: Fix regression in scipy that relied on quirky behaviour

Scipy needs `.__dict__['coeffs']` to work, so we can't call the member _coeffs

1 files changed, 10 insertions, 0 deletions

diff --git a/numpy/lib/polynomial.py b/numpy/lib/polynomial.py
index 50e6d8db2..ddff0d3b0 100644
--- a/numpy/lib/polynomial.py
+++ b/numpy/lib/polynomial.py
@@ -1059,6 +1059,16 @@ class poly1d(object):
         """ The roots of the polynomial, where self(x) == 0 """
         return roots(self._coeffs)
 
+    # our internal _coeffs property need to be backed by __dict__['coeffs'] for
+    # scipy to work correctly. Note that as a result, the getter for .coeffs
+    # does not run unless accessed through one of its aliases.
+    @property
+    def _coeffs(self):
+        return self.__dict__['coeffs']
+    @_coeffs.setter
+    def _coeffs(self, coeffs):
+        self.__dict__['coeffs'] = coeffs
+
     # alias attributes
     r = roots
     c = coef = coefficients = coeffs