Merge branch 'master' into mhucka-add-security-policy

.github/workflows/ci.yml

@@ -1,18 +1,32 @@
 name: Continuous Integration
-on: [pull_request]
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+    branches:
+      - master
+
+  merge_group:
+    types:
+      - checks_requested
+
+  push:
+    branches:
+      - master
 
 jobs:
   format:
     name: Format check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: actions/setup-python@v1
+      - uses: actions/setup-python@v5
         with:
           python-version: '3.10'
           architecture: 'x64'
+          cache: pip
       - name: Install requirements
         run: pip install -r dev_tools/requirements/envs/format.env.txt
       - name: Format
@@ -21,11 +35,12 @@ jobs:
     name: Type check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v1
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: '3.10'
           architecture: 'x64'
+          cache: pip
       - name: Install requirements
         run: pip install -r dev_tools/requirements/envs/mypy.env.txt
       - name: Type check
@@ -34,11 +49,12 @@ jobs:
     name: Lint check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v1
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: '3.10'
           architecture: 'x64'
+          cache: pip
       - name: Install requirements
         run: pip install -r dev_tools/requirements/envs/pylint.env.txt
       - name: Lint
@@ -47,10 +63,11 @@ jobs:
     name: Pytest max compat
     runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: 3.8
+          cache: pip
       - name: Install requirements
         run: |
           pip install -r dev_tools/requirements/max_compat/pytest-max-compat.env.txt
@@ -63,16 +80,18 @@ jobs:
     strategy:
       matrix:
         os: [ ubuntu-latest, macos-latest, windows-latest ]
+        cirq-version: [ 1.4.1 ]
       fail-fast: false
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: '3.10'
+          cache: pip
       - name: Install requirements
         run: |
           pip install -r dev_tools/requirements/envs/pytest.env.txt
-          pip install cirq-core${{matrix.cirq-version}}
+          pip install cirq-core==${{matrix.cirq-version}}
       - name: Pytest check
         run: check/pytest
         shell: bash
@@ -82,30 +101,33 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest]
+        cirq-version: [ 1.4.1 ]
       fail-fast: false
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: '3.10'
+          cache: pip
       - name: Install requirements
         run: |
           pip install -r dev_tools/requirements/envs/pytest-extra.env.txt
-          pip install cirq-core${{matrix.cirq-version}}
+          pip install cirq-core==${{matrix.cirq-version}}
       - name: Pytest check resources
         run: check/pytest -m 'not slow' src/openfermion/resource_estimates
         shell: bash
   coverage:
     name: Coverage check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: actions/setup-python@v1
+      - uses: actions/setup-python@v5
         with:
           python-version: '3.10'
+          cache: pip
       - name: Install requirements
         run: pip install -r dev_tools/requirements/envs/pytest.env.txt
       - name: Coverage check
-        run: check/pytest-and-incremental-coverage
+        run: check/pytest-and-incremental-coverage

.github/workflows/nightly.yml

@@ -14,10 +14,11 @@ jobs:
         python-version: [ '3.10' ]
       fail-fast: false
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
+          cache: pip
       - name: Install requirements
         run: |
           pip install -r dev_tools/requirements/envs/pytest.env.txt

docs/tutorials/intro_workshop_exercises.ipynb

@@ -122,7 +122,7 @@
     "operator*, and we refer to creation and annihilation operators as\n",
     "fermionic *ladder operators*.\n",
     "    \n",
-    "The canonical anticommutation relations impose a number of consequences on the structure of the vector space on which the ladder operators act; see [Michael Nielsen's notes](http://michaelnielsen.org/blog/archive/notes/fermions_and_jordan_wigner.pdf) for a good discussion.\n",
+    "The canonical anticommutation relations impose a number of consequences on the structure of the vector space on which the ladder operators act; see [Michael Nielsen's notes](https://futureofmatter.com/assets/fermions_and_jordan_wigner.pdf) for a good discussion.\n",
     "\n",
     "The electronic structure Hamiltonian is commonly written in the form\n",
     "$$\n",

docs/tutorials/jordan_wigner_and_bravyi_kitaev_transforms.ipynb

@@ -136,7 +136,7 @@
     "-   The annihilation operators $a_p$ act on this basis as follows:\n",
     "    $$\\begin{aligned} a_p \\lvert n_0, \\ldots, n_{p-1}, 1, n_{p+1}, \\ldots, n_{N-1} \\rangle &= (-1)^{\\sum_{q=0}^{p-1} n_q} \\lvert n_0, \\ldots, n_{p-1}, 0, n_{p+1}, \\ldots, n_{N-1} \\rangle \\,, \\\\ a_p \\lvert n_0, \\ldots, n_{p-1}, 0, n_{p+1}, \\ldots, n_{N-1} \\rangle &= 0 \\,.\\end{aligned}$$\n",
     "    \n",
-    "See [here](http://michaelnielsen.org/blog/archive/notes/fermions_and_jordan_wigner.pdf) for a derivation and discussion of these\n",
+    "See [here](https://futureofmatter.com/assets/fermions_and_jordan_wigner.pdf) for a derivation and discussion of these\n",
     "consequences.\n",
     "\n",
     "## Mapping fermions to qubits with transforms\n",

src/openfermion/transforms/repconversions/operator_tapering.py

@@ -56,7 +56,7 @@ def freeze_orbitals(fermion_operator, occupied, unoccupied=None, prune=True):
             n_swaps = 0  # Number of swaps that have been done
 
             for op in enumerate(reversed(term)):
-                if op[1][0] is item[0]:
+                if op[1][0] == item[0]:
                     n_ops += 1
 
                     # Determine number of swaps needed to bring the op in