diff --git a/pyzx/circuit/qasmparser.py b/pyzx/circuit/qasmparser.py
index ca10fe8e..4e7539ef 100644
--- a/pyzx/circuit/qasmparser.py
+++ b/pyzx/circuit/qasmparser.py
@@ -169,13 +169,13 @@ def parse_command(self, c: str, registers: Dict[str,Tuple[int,int]]) -> List[Gat
                 for g in circ.gates:
                     gates.append(g.reposition(argset))
                 continue
-            if name in ("x", "z", "s", "t", "h", "sdg", "tdg"):
-                if name in ("sdg", "tdg"):
+            if name in ('x', 'z', 's', 't', 'h', 'sdg', 'tdg'):
+                if name in ('sdg', 'tdg'):
                     g = qasm_gate_table[name](argset[0],adjoint=True) # type: ignore # mypy can't handle -
                 else: g = qasm_gate_table[name](argset[0]) # type: ignore # - Gate subclasses with different numbers of parameters
                 gates.append(g)
                 continue
-            if name.startswith(("rx", "ry", "rz", "p", "u1", "crz")):
+            if name.startswith(('rx', 'ry', 'rz', 'p', 'u1', 'crz')):
                 i = name.find('(')
                 j = name.find(')')
                 if i == -1 or j == -1: raise TypeError("Invalid specification {}".format(name))
@@ -201,7 +201,7 @@ def parse_command(self, c: str, registers: Dict[str,Tuple[int,int]]) -> List[Gat
                     gates.append(NOT(argset[0]))
                     gates.append(ZPhase(argset[0],phase=-phase/2))
                     gates.append(NOT(argset[0]))
-                elif name.startswith("ry"): gates.append(YPhase(argset[0],phase=phase))
+                elif name.startswith('ry'): gates.append(YPhase(argset[0],phase=phase))
                 else: raise TypeError("Invalid specification {}".format(name))
                 continue
             if name.startswith('u2') or name.startswith('u3'): # see https://arxiv.org/pdf/1707.03429.pdf
@@ -225,11 +225,11 @@ def parse_command(self, c: str, registers: Dict[str,Tuple[int,int]]) -> List[Gat
                     gates.append(XPhase(argset[0],phase=Fraction(1,2)))
                     gates.append(ZPhase(argset[0],phase=(phases[1]+3)%2))
                     continue
-            if name in ("cx","CX","cz","ch", "swap"):
+            if name in ('cx', 'CX', 'cz', 'ch', 'swap'):
                 g = qasm_gate_table[name](control=argset[0],target=argset[1]) # type: ignore
                 gates.append(g)
                 continue
-            if name in ("ccx", "ccz"):
+            if name in ('ccx', 'ccz'):
                 g = qasm_gate_table[name](ctrl1=argset[0],ctrl2=argset[1],target=argset[2]) # type: ignore
                 gates.append(g)
                 continue
diff --git a/tests/test_cnot_mapper.py b/tests/test_cnot_mapper.py
index 56aee605..cd1c9235 100644
--- a/tests/test_cnot_mapper.py
+++ b/tests/test_cnot_mapper.py
@@ -1,3 +1,20 @@
+# PyZX - Python library for quantum circuit rewriting
+#        and optimization using the ZX-calculus
+# Copyright (C) 2018 - Aleks Kissinger and John van de Wetering
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#    http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
 import copy
 import unittest
 import sys
diff --git a/tests/test_phasepoly.py b/tests/test_phasepoly.py
index 6ea18584..f4f17437 100644
--- a/tests/test_phasepoly.py
+++ b/tests/test_phasepoly.py
@@ -1,3 +1,20 @@
+# PyZX - Python library for quantum circuit rewriting
+#        and optimization using the ZX-calculus
+# Copyright (C) 2018 - Aleks Kissinger and John van de Wetering
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#    http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
 from typing import List
 import unittest
 import sys, os
diff --git a/tests/test_ry.py b/tests/test_ry.py
index 96508cba..2506c592 100644
--- a/tests/test_ry.py
+++ b/tests/test_ry.py
@@ -1,7 +1,20 @@
+# PyZX - Python library for quantum circuit rewriting
+#        and optimization using the ZX-calculus
+# Copyright (C) 2018 - Aleks Kissinger and John van de Wetering
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#    http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+
 import unittest
 import random
 import sys