Fix typos in comments.

mypy/build.py

@@ -1741,7 +1741,7 @@ class State:
     # iteration over dependencies.
     # They should be managed with add_dependency and suppress_dependency.
     dependencies = None  # type: List[str]  # Modules directly imported by the module
-    dependencies_set = None  # type: Set[str]  # The same but as a set for deduplication purposes
+    dependencies_set = None  # type: Set[str]  # The same but as a set for duplication purposes
     suppressed = None  # type: List[str]  # Suppressed/missing dependencies
     suppressed_set = None  # type: Set[str]  # Suppressed/missing dependencies
     priorities = None  # type: Dict[str, int]
@@ -2098,7 +2098,7 @@ def semantic_analysis_pass1(self) -> None:
         analyzer = SemanticAnalyzerPreAnalysis()
         with self.wrap_context():
             analyzer.visit_file(self.tree, self.xpath, self.id, options)
-        # TODO: Do this while contructing the AST?
+        # TODO: Do this while constructing the AST?
         self.tree.names = SymbolTable()
         if options.allow_redefinition:
             # Perform renaming across the AST to allow variable redefinitions

mypy/checker.py

@@ -2188,7 +2188,7 @@ def try_infer_partial_generic_type_from_assignment(self,
             if op != '=' and (typ.type.fullname, op) not in self.partial_type_augmented_ops:
                 return
             # TODO: some logic here duplicates the None partial type counterpart
-            #       inlined in check_assignment(), see # 8043.
+            #       inlined in check_assignment(), see #8043 (https://github.com/python/mypy/issues/8043).
             partial_types = self.find_partial_types(var)
             if partial_types is None:
                 return
@@ -2905,7 +2905,7 @@ def infer_partial_type(self, name: Var, lvalue: Lvalue, init_type: Type) -> bool
         return True
 
     def is_valid_defaultdict_partial_value_type(self, t: ProperType) -> bool:
-        """Check if t can be used as the basis for a partial defaultddict value type.
+        """Check if t can be used as the basis for a partial defaultdict value type.
 
         Examples:
 
@@ -4499,15 +4499,15 @@ def refine_identity_comparison_expression(self,
         if target is None:
             return {}, {}
 
-        # If possible, use an unassignable expression as the target.
+        # If possible, use an nonassignable expression as the target.
         # We skip refining the type of the target below, so ideally we'd
         # want to pick an expression we were going to skip anyways.
         singleton_index = -1
         for i in possible_target_indices:
             if i not in narrowable_operand_indices:
                 singleton_index = i
 
-        # But if none of the possible singletons are unassignable ones, we give up
+        # But if none of the possible singletons are nonassignable ones, we give up
         # and arbitrarily pick the last item, mostly because other parts of the
         # type narrowing logic bias towards picking the rightmost item and it'd be
         # nice to stay consistent.
@@ -5477,7 +5477,7 @@ def overload_can_never_match(signature: CallableType, other: CallableType) -> bo
 
 
 def is_more_general_arg_prefix(t: FunctionLike, s: FunctionLike) -> bool:
-    """Does t have wider arguments than s?"""
+    """Does it have wider arguments than s?"""
     # TODO should an overload with additional items be allowed to be more
     #      general than one with fewer items (or just one item)?
     if isinstance(t, CallableType):

mypy/checkexpr.py

@@ -90,7 +90,7 @@
 MAX_UNIONS = 5  # type: Final
 
 
-# Types considered safe for comparisons with --strict-equality due to known behaviour of __eq__.
+# Types considered safe for comparisons with --strict-equality due to known behavior of __eq__.
 # NOTE: All these types are subtypes of AbstractSet.
 OVERLAPPING_TYPES_WHITELIST = ['builtins.set', 'builtins.frozenset',
                                'typing.KeysView', 'typing.ItemsView']  # type: Final