From 22680e2b3a61f17749beafe408ac716d06b1dcbd Mon Sep 17 00:00:00 2001
From: DNIIBOY <daniel.nettelfield@gmail.com>
Date: Sat, 24 Feb 2024 21:09:39 +0100
Subject: [PATCH 1/3] Add __hash__ method to Substance class

---
 chempy/chemistry.py | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/chempy/chemistry.py b/chempy/chemistry.py
index f20f75bb..85685827 100644
--- a/chempy/chemistry.py
+++ b/chempy/chemistry.py
@@ -98,6 +98,17 @@ def __eq__(self, other):
                 return False
         return True
 
+    def __hash__(self) -> int:
+        return sum(
+            map(
+                hash,
+                (
+                    getattr(self, k)
+                    for k in self.attrs
+                ),
+            )
+        )
+
     @property
     def charge(self):
         """Convenience property for accessing ``composition[0]``"""

From d3c617fb5be979f574bbb5930ff54b83d999ec34 Mon Sep 17 00:00:00 2001
From: DNIIBOY <daniel.nettelfield@gmail.com>
Date: Sat, 24 Feb 2024 21:22:30 +0100
Subject: [PATCH 2/3] Add passing test case

---
 chempy/chemistry.py            | 2 +-
 chempy/tests/test_chemistry.py | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/chempy/chemistry.py b/chempy/chemistry.py
index 85685827..5e45ea3a 100644
--- a/chempy/chemistry.py
+++ b/chempy/chemistry.py
@@ -104,7 +104,7 @@ def __hash__(self) -> int:
                 hash,
                 (
                     getattr(self, k)
-                    for k in self.attrs
+                    for k in ("name", "latex_name", "unicode_name", "html_name")
                 ),
             )
         )
diff --git a/chempy/tests/test_chemistry.py b/chempy/tests/test_chemistry.py
index 8c5aa811..ec823837 100644
--- a/chempy/tests/test_chemistry.py
+++ b/chempy/tests/test_chemistry.py
@@ -40,6 +40,7 @@ def test_Substance():
     assert s.composition == {0: 1, 1: 1}
     assert s.charge == 1
     assert abs(s.mass - 1.008) < 1e-3
+    assert s in {s: 1}
 
 
 def test_Substance__2():

From 5c5f09f15f0967c7b09a4f46d282b64f22dd9a29 Mon Sep 17 00:00:00 2001
From: DNIIBOY <daniel.nettelfield@gmail.com>
Date: Sun, 25 Feb 2024 17:49:23 +0100
Subject: [PATCH 3/3] Update __hash__ to use all of self.attrs

---
 chempy/chemistry.py            | 17 ++++++++---------
 chempy/tests/test_chemistry.py |  1 +
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/chempy/chemistry.py b/chempy/chemistry.py
index 5e45ea3a..e225dc7f 100644
--- a/chempy/chemistry.py
+++ b/chempy/chemistry.py
@@ -99,15 +99,14 @@ def __eq__(self, other):
         return True
 
     def __hash__(self) -> int:
-        return sum(
-            map(
-                hash,
-                (
-                    getattr(self, k)
-                    for k in ("name", "latex_name", "unicode_name", "html_name")
-                ),
-            )
-        )
+        hashed_values = []
+        for key in self.attrs:
+            value = getattr(self, key)
+            if isinstance(value, dict):
+                hashed_values.append(hash(tuple(sorted(value.items()))))
+            else:
+                hashed_values.append(hash(value))
+        return sum(hashed_values)
 
     @property
     def charge(self):
diff --git a/chempy/tests/test_chemistry.py b/chempy/tests/test_chemistry.py
index ec823837..2307be57 100644
--- a/chempy/tests/test_chemistry.py
+++ b/chempy/tests/test_chemistry.py
@@ -41,6 +41,7 @@ def test_Substance():
     assert s.charge == 1
     assert abs(s.mass - 1.008) < 1e-3
     assert s in {s: 1}
+    assert hash(s) != hash(Substance.from_formula("He"))
 
 
 def test_Substance__2():