From 65938f7647d6445c590870e3d9e72415970af6f8 Mon Sep 17 00:00:00 2001
From: Mark Mikofski <bwana.marko@yahoo.com>
Date: Tue, 4 Sep 2018 10:03:49 -0700
Subject: [PATCH] BUG: fix brentq doesn't raise error in singlediode

* if `brentq` is called in `singlediode.py` but no SciPy, then should raise an exception
* currently using `NotImplemented` raises TypeError: 'NotImplementedType' object is not callable because `NotImplemented` is a constant
---
 pvlib/singlediode.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pvlib/singlediode.py b/pvlib/singlediode.py
index cb5b8e6b13..d0ad27e995 100644
--- a/pvlib/singlediode.py
+++ b/pvlib/singlediode.py
@@ -13,7 +13,8 @@
 try:
     from scipy.optimize import brentq
 except ImportError:
-    brentq = NotImplemented
+    def brentq(): raise NotImplementedError(
+        "brentq can't be imported because scipy isn't installed")
 
 # FIXME: change this to newton when scipy-1.2 is released
 try: