Python: Consistenly use parameter instead of argument in docs

The Python 3 FAQ states that this is the right thing [0]

It sadly doesn't align 100% with PEP8, which calls them for "arguments" [1], but
after discussion with Taus, we decided to go with "parameter" everywhere to be
consistent.

[0] https://docs.python.org/3/faq/programming.html#faq-argument-vs-parameter
[1] https://www.python.org/dev/peps/pep-0008/#function-and-method-arguments

python/ql/src/Functions/NonCls.qhelp

@@ -5,14 +5,14 @@
 
 
 <overview>
-<p> The first argument of a class method, a new method or any metaclass method
-should be called <code>cls</code>. This makes the purpose of the argument clear to other developers.
+<p> The first parameter of a class method, a new method or any metaclass method
+should be called <code>cls</code>. This makes the purpose of the parameter clear to other developers.
 </p>
 
 </overview>
 <recommendation>
 
-<p>Change the name of the first argument to <code>cls</code> as recommended by the style guidelines
+<p>Change the name of the first parameter to <code>cls</code> as recommended by the style guidelines
 in PEP 8.</p>
 
 </recommendation>

python/ql/src/Functions/NonCls.ql

@@ -1,7 +1,7 @@
 /**
  * @name First parameter of a class method is not named 'cls'
- * @description Using an alternative name for the first argument of a class method makes code more
- *              difficult to read; PEP8 states that the first argument to class methods should be 'cls'.
+ * @description Using an alternative name for the first parameter of a class method makes code more
+ *              difficult to read; PEP8 states that the first parameter to class methods should be 'cls'.
  * @kind problem
  * @tags maintainability
  *       readability
@@ -38,10 +38,10 @@ not first_arg_cls(f) and classmethod_decorators_only(f) and
 not f.getName() = "__new__" and
 (
   if exists(f.getArgName(0)) then
-      message = "Class methods or methods of a type deriving from type should have 'cls', rather than '" + 
-            f.getArgName(0) + "', as their first argument."
+      message = "Class methods or methods of a type deriving from type should have 'cls', rather than '" +
+            f.getArgName(0) + "', as their first parameter."
   else
-      message = "Class methods or methods of a type deriving from type should have 'cls' as their first argument."
+      message = "Class methods or methods of a type deriving from type should have 'cls' as their first parameter."
 )
 
 select f, message

python/ql/src/Functions/NonSelf.py

@@ -1,9 +1,9 @@
 class Point:
-    def __init__(val, x, y):  # first argument is mis-named 'val'
+    def __init__(val, x, y):  # first parameter is mis-named 'val'
         val._x = x
         val._y = y
-		
+
 class Point2:
-    def __init__(self, x, y):  # first argument is correctly named 'self'
+    def __init__(self, x, y):  # first parameter is correctly named 'self'
         self._x = x
         self._y = y

python/ql/src/Functions/NonSelf.ql

@@ -1,7 +1,7 @@
 /**
- * @name First argument of a method is not named 'self'
- * @description Using an alternative name for the first argument of an instance method makes
- *              code more difficult to read; PEP8 states that the first argument to instance
+ * @name First parameter of a method is not named 'self'
+ * @description Using an alternative name for the first parameter of an instance method makes
+ *              code more difficult to read; PEP8 states that the first parameter to instance
  *              methods should be 'self'.
  * @kind problem
  * @tags maintainability

python/ql/test/query-tests/Functions/general/NonCls.expected

@@ -1,3 +1,3 @@
-| argument_names.py:17:5:17:24 | Function n_cmethod | Class methods or methods of a type deriving from type should have 'cls', rather than 'self', as their first argument. |
-| argument_names.py:22:5:22:21 | Function n_cmethod2 | Class methods or methods of a type deriving from type should have 'cls' as their first argument. |
-| argument_names.py:37:5:37:20 | Function c_method | Class methods or methods of a type deriving from type should have 'cls', rather than 'y', as their first argument. |
+| parameter_names.py:17:5:17:24 | Function n_cmethod | Class methods or methods of a type deriving from type should have 'cls', rather than 'self', as their first parameter. |
+| parameter_names.py:22:5:22:21 | Function n_cmethod2 | Class methods or methods of a type deriving from type should have 'cls' as their first parameter. |
+| parameter_names.py:37:5:37:20 | Function c_method | Class methods or methods of a type deriving from type should have 'cls', rather than 'y', as their first parameter. |

python/ql/test/query-tests/Functions/general/NonSelf.expected

@@ -1,4 +1,4 @@
-| argument_names.py:50:5:50:20 | Function __init__ | Normal methods should have 'self', rather than 'x', as their first parameter. |
-| argument_names.py:53:5:53:20 | Function s_method | Normal methods should have 'self', rather than 'y', as their first parameter. |
-| argument_names.py:56:5:56:20 | Function s_method2 | Normal methods should have at least one parameter (the first of which should be 'self'). |
 | om_test.py:71:5:71:19 | Function __repr__ | Normal methods should have at least one parameter (the first of which should be 'self'). |
+| parameter_names.py:50:5:50:20 | Function __init__ | Normal methods should have 'self', rather than 'x', as their first parameter. |
+| parameter_names.py:53:5:53:20 | Function s_method | Normal methods should have 'self', rather than 'y', as their first parameter. |
+| parameter_names.py:56:5:56:20 | Function s_method2 | Normal methods should have at least one parameter (the first of which should be 'self'). |

python/ql/test/query-tests/Functions/general/parameter_names.py

@@ -1,6 +1,6 @@
-# Using name other than 'self' for first argument in methods.
-# This shouldn't apply to classmethods (first argument should be 'cls' or similar)
-# or static methods (first argument can be anything)
+# Using name other than 'self' for first parameter in methods.
+# This shouldn't apply to classmethods (first parameter should be 'cls' or similar)
+# or static methods (first parameter can be anything)
 
 
 class Normal(object):