Make mypy --no-implicit-optional clean for strict Optional-checked files (#3699)

* Make mypy --no-implicit-optinal clean for strict Optional-checked files

* fix lint errors

* quote optionals

Author: ddfisher

mypy/binder.py

@@ -89,7 +89,7 @@ def __init__(self) -> None:
         self.break_frames = []  # type: List[int]
         self.continue_frames = []  # type: List[int]
 
-    def _add_dependencies(self, key: Key, value: Key = None) -> None:
+    def _add_dependencies(self, key: Key, value: Optional[Key] = None) -> None:
         if value is None:
             value = key
         else:

mypy/checkexpr.py

@@ -2204,7 +2204,7 @@ def visit_backquote_expr(self, e: BackquoteExpr) -> Type:
 
     def accept(self,
                node: Expression,
-               type_context: Type = None,
+               type_context: Optional[Type] = None,
                allow_none_return: bool = False,
                always_allow_any: bool = False,
                ) -> Type:

mypy/checkmember.py

@@ -38,7 +38,7 @@ def analyze_member_access(name: str,
                           msg: MessageBuilder, *,
                           original_type: Type,
                           chk: 'mypy.checker.TypeChecker',
-                          override_info: TypeInfo = None) -> Type:
+                          override_info: Optional[TypeInfo] = None) -> Type:
     """Return the type of attribute `name` of typ.
 
     This is a general operation that supports various different variations:
@@ -603,7 +603,7 @@ def map_type_from_supertype(typ: Type, sub_info: TypeInfo,
 F = TypeVar('F', bound=FunctionLike)
 
 
-def bind_self(method: F, original_type: Type = None, is_classmethod: bool = False) -> F:
+def bind_self(method: F, original_type: Optional[Type] = None, is_classmethod: bool = False) -> F:
     """Return a copy of `method`, with the type of its first parameter (usually
     self or cls) bound to original_type.
 

mypy/checkstrformat.py

@@ -334,6 +334,6 @@ def named_type(self, name: str) -> Instance:
         """
         return self.chk.named_type(name)
 
-    def accept(self, expr: Expression, context: Type = None) -> Type:
+    def accept(self, expr: Expression, context: Optional[Type] = None) -> Type:
         """Type check a node. Alias for TypeChecker.accept."""
         return self.chk.expr_checker.accept(expr, context)

mypy/errors.py

@@ -65,8 +65,8 @@ def __init__(self,
                  message: str,
                  blocker: bool,
                  only_once: bool,
-                 origin: Tuple[str, int] = None,
-                 target: str = None) -> None:
+                 origin: Optional[Tuple[str, int]] = None,
+                 target: Optional[str] = None) -> None:
         self.import_ctx = import_ctx
         self.file = file
         self.module = module
@@ -175,7 +175,9 @@ def simplify_path(self, file: str) -> str:
         file = os.path.normpath(file)
         return remove_path_prefix(file, self.ignore_prefix)
 
-    def set_file(self, file: str, module: Optional[str], ignored_lines: Set[int] = None) -> None:
+    def set_file(self, file: str,
+                 module: Optional[str],
+                 ignored_lines: Optional[Set[int]] = None) -> None:
         """Set the path and module id of the current file."""
         # The path will be simplified later, in render_messages. That way
         #  * 'file' is always a key that uniquely identifies a source file
@@ -251,9 +253,15 @@ def set_import_context(self, ctx: List[Tuple[str, int]]) -> None:
         """Replace the entire import context with a new value."""
         self.import_ctx = ctx[:]
 
-    def report(self, line: int, column: int, message: str, blocker: bool = False,
-               severity: str = 'error', file: str = None, only_once: bool = False,
-               origin_line: int = None) -> None:
+    def report(self,
+               line: int,
+               column: int,
+               message: str,
+               blocker: bool = False,
+               severity: str = 'error',
+               file: Optional[str] = None,
+               only_once: bool = False,
+               origin_line: Optional[int] = None) -> None:
         """Report message at the given line using the current error context.
 
         Args:

mypy/fastparse.py

@@ -60,7 +60,9 @@
 TYPE_COMMENT_AST_ERROR = 'invalid type comment or annotation'
 
 
-def parse(source: Union[str, bytes], fnam: str = None, errors: Errors = None,
+def parse(source: Union[str, bytes],
+          fnam: Optional[str] = None,
+          errors: Optional[Errors] = None,
           options: Options = Options()) -> MypyFile:
 
     """Parse a source file, without doing any semantic analysis.

mypy/fastparse2.py

@@ -73,7 +73,9 @@
 TYPE_COMMENT_AST_ERROR = 'invalid type comment'
 
 
-def parse(source: Union[str, bytes], fnam: str = None, errors: Errors = None,
+def parse(source: Union[str, bytes],
+          fnam: Optional[str] = None,
+          errors: Optional[Errors] = None,
           options: Options = Options()) -> MypyFile:
     """Parse a source file, without doing any semantic analysis.
 

mypy/messages.py

@@ -158,26 +158,26 @@ def is_errors(self) -> bool:
         return self.errors.is_errors()
 
     def report(self, msg: str, context: Context, severity: str,
-               file: str = None, origin: Context = None) -> None:
+               file: Optional[str] = None, origin: Optional[Context] = None) -> None:
         """Report an error or note (unless disabled)."""
         if self.disable_count <= 0:
             self.errors.report(context.get_line() if context else -1,
                                context.get_column() if context else -1,
                                msg.strip(), severity=severity, file=file,
                                origin_line=origin.get_line() if origin else None)
 
-    def fail(self, msg: str, context: Context, file: str = None,
-             origin: Context = None) -> None:
+    def fail(self, msg: str, context: Context, file: Optional[str] = None,
+             origin: Optional[Context] = None) -> None:
         """Report an error message (unless disabled)."""
         self.report(msg, context, 'error', file=file, origin=origin)
 
-    def note(self, msg: str, context: Context, file: str = None,
-             origin: Context = None) -> None:
+    def note(self, msg: str, context: Context, file: Optional[str] = None,
+             origin: Optional[Context] = None) -> None:
         """Report a note (unless disabled)."""
         self.report(msg, context, 'note', file=file, origin=origin)
 
-    def warn(self, msg: str, context: Context, file: str = None,
-             origin: Context = None) -> None:
+    def warn(self, msg: str, context: Context, file: Optional[str] = None,
+             origin: Optional[Context] = None) -> None:
         """Report a warning message (unless disabled)."""
         self.report(msg, context, 'warning', file=file, origin=origin)
 

mypy/nodes.py

@@ -23,7 +23,7 @@ def __init__(self, line: int = -1, column: int = -1) -> None:
         self.line = line
         self.column = column
 
-    def set_line(self, target: Union['Context', int], column: int = None) -> None:
+    def set_line(self, target: Union['Context', int], column: Optional[int] = None) -> None:
         """If target is a node, pull line (and column) information
         into this node. If column is specified, this will override any column
         information coming from a node.
@@ -254,7 +254,7 @@ def __init__(self,
                  defs: List[Statement],
                  imports: List['ImportBase'],
                  is_bom: bool = False,
-                 ignored_lines: Set[int] = None) -> None:
+                 ignored_lines: Optional[Set[int]] = None) -> None:
         self.defs = defs
         self.line = 1  # Dummy line number
         self.imports = imports
@@ -445,7 +445,7 @@ class Argument(Node):
 
     def __init__(self, variable: 'Var', type_annotation: 'Optional[mypy.types.Type]',
             initializer: Optional[Expression], kind: int,
-            initialization_statement: Optional['AssignmentStmt'] = None) -> None:
+            initialization_statement: 'Optional[AssignmentStmt]' = None) -> None:
         self.variable = variable
 
         self.type_annotation = type_annotation
@@ -457,7 +457,7 @@ def __init__(self, variable: 'Var', type_annotation: 'Optional[mypy.types.Type]'
 
         self.kind = kind
 
-    def _initialization_statement(self) -> Optional['AssignmentStmt']:
+    def _initialization_statement(self) -> 'Optional[AssignmentStmt]':
         """Convert the initializer into an assignment statement.
         """
         if not self.initializer:
@@ -468,7 +468,7 @@ def _initialization_statement(self) -> Optional['AssignmentStmt']:
         assign = AssignmentStmt([lvalue], rvalue)
         return assign
 
-    def set_line(self, target: Union[Context, int], column: int = None) -> None:
+    def set_line(self, target: Union[Context, int], column: Optional[int] = None) -> None:
         super().set_line(target, column)
 
         if self.initializer:
@@ -507,7 +507,7 @@ class FuncItem(FuncBase):
     ]
 
     def __init__(self, arguments: List[Argument], body: 'Block',
-                 typ: 'mypy.types.FunctionLike' = None) -> None:
+                 typ: 'Optional[mypy.types.FunctionLike]' = None) -> None:
         self.arguments = arguments
         self.arg_names = [arg.variable.name() for arg in self.arguments]
         self.arg_kinds = [arg.kind for arg in self.arguments]
@@ -525,7 +525,7 @@ def __init__(self, arguments: List[Argument], body: 'Block',
     def max_fixed_argc(self) -> int:
         return self.max_pos
 
-    def set_line(self, target: Union[Context, int], column: int = None) -> None:
+    def set_line(self, target: Union[Context, int], column: Optional[int] = None) -> None:
         super().set_line(target, column)
         for arg in self.arguments:
             arg.set_line(self.line, self.column)
@@ -554,7 +554,7 @@ def __init__(self,
                  name: str,              # Function name
                  arguments: List[Argument],
                  body: 'Block',
-                 typ: 'mypy.types.FunctionLike' = None) -> None:
+                 typ: 'Optional[mypy.types.FunctionLike]' = None) -> None:
         super().__init__(arguments, body, typ)
         self._name = name
 
@@ -679,7 +679,7 @@ class Var(SymbolNode):
         'is_classvar'
     ]
 
-    def __init__(self, name: str, type: 'mypy.types.Type' = None) -> None:
+    def __init__(self, name: str, type: 'Optional[mypy.types.Type]' = None) -> None:
         self._name = name
         self.type = type
         if self.type is None:
@@ -738,10 +738,10 @@ class ClassDef(Statement):
     def __init__(self,
                  name: str,
                  defs: 'Block',
-                 type_vars: List['mypy.types.TypeVarDef'] = None,
-                 base_type_exprs: List[Expression] = None,
-                 metaclass: str = None,
-                 keywords: List[Tuple[str, Expression]] = None) -> None:
+                 type_vars: Optional[List['mypy.types.TypeVarDef']] = None,
+                 base_type_exprs: Optional[List[Expression]] = None,
+                 metaclass: Optional[str] = None,
+                 keywords: Optional[List[Tuple[str, Expression]]] = None) -> None:
         self.name = name
         self.defs = defs
         self.type_vars = type_vars or []
@@ -848,7 +848,7 @@ class AssignmentStmt(Statement):
     new_syntax = False  # type: bool
 
     def __init__(self, lvalues: List[Lvalue], rvalue: Expression,
-                 type: 'mypy.types.Type' = None, new_syntax: bool = False) -> None:
+                 type: 'Optional[mypy.types.Type]' = None, new_syntax: bool = False) -> None:
         self.lvalues = lvalues
         self.rvalue = rvalue
         self.type = type
@@ -900,8 +900,12 @@ class ForStmt(Statement):
     else_body = None  # type: Optional[Block]
     is_async = False  # True if `async for ...` (PEP 492, Python 3.5)
 
-    def __init__(self, index: Lvalue, expr: Expression, body: Block,
-                 else_body: Optional[Block], index_type: 'mypy.types.Type' = None) -> None:
+    def __init__(self,
+                 index: Lvalue,
+                 expr: Expression,
+                 body: Block,
+                 else_body: Optional[Block],
+                 index_type: 'Optional[mypy.types.Type]' = None) -> None:
         self.index = index
         self.index_type = index_type
         self.expr = expr
@@ -926,7 +930,7 @@ class AssertStmt(Statement):
     expr = None  # type: Expression
     msg = None  # type: Optional[Expression]
 
-    def __init__(self, expr: Expression, msg: Expression = None) -> None:
+    def __init__(self, expr: Expression, msg: Optional[Expression] = None) -> None:
         self.expr = expr
         self.msg = msg
 
@@ -996,7 +1000,7 @@ class TryStmt(Statement):
     else_body = None  # type: Optional[Block]
     finally_body = None  # type: Optional[Block]
 
-    def __init__(self, body: Block, vars: List[Optional['NameExpr']],
+    def __init__(self, body: Block, vars: List['Optional[NameExpr]'],
                  types: List[Optional[Expression]],
                  handlers: List[Block], else_body: Optional[Block],
                  finally_body: Optional[Block]) -> None:
@@ -1020,7 +1024,7 @@ class WithStmt(Statement):
     is_async = False  # True if `async with ...` (PEP 492, Python 3.5)
 
     def __init__(self, expr: List[Expression], target: List[Optional[Lvalue]],
-                 body: Block, target_type: 'mypy.types.Type' = None) -> None:
+                 body: Block, target_type: 'Optional[mypy.types.Type]' = None) -> None:
         self.expr = expr
         self.target = target
         self.target_type = target_type
@@ -1038,7 +1042,10 @@ class PrintStmt(Statement):
     # The file-like target object (given using >>).
     target = None  # type: Optional[Expression]
 
-    def __init__(self, args: List[Expression], newline: bool, target: Expression = None) -> None:
+    def __init__(self,
+                 args: List[Expression],
+                 newline: bool,
+                 target: Optional[Expression] = None) -> None:
         self.args = args
         self.newline = newline
         self.target = target
@@ -1292,8 +1299,12 @@ class CallExpr(Expression):
     # cast(...) this is a CastExpr.
     analyzed = None  # type: Optional[Expression]
 
-    def __init__(self, callee: Expression, args: List[Expression], arg_kinds: List[int],
-                 arg_names: List[Optional[str]] = None, analyzed: Expression = None) -> None:
+    def __init__(self,
+                 callee: Expression,
+                 args: List[Expression],
+                 arg_kinds: List[int],
+                 arg_names: Optional[List[Optional[str]]] = None,
+                 analyzed: Optional[Expression] = None) -> None:
         if not arg_names:
             arg_names = [None] * len(args)
 
@@ -1813,7 +1824,7 @@ class TypeAliasExpr(Expression):
     in_runtime = False  # type: bool
 
     def __init__(self, type: 'mypy.types.Type', tvars: List[str],
-                 fallback: 'mypy.types.Type' = None, in_runtime: bool = False) -> None:
+                 fallback: 'Optional[mypy.types.Type]' = None, in_runtime: bool = False) -> None:
         self.type = type
         self.fallback = fallback
         self.in_runtime = in_runtime
@@ -2038,14 +2049,14 @@ def is_generic(self) -> bool:
         """Is the type generic (i.e. does it have type variables)?"""
         return len(self.type_vars) > 0
 
-    def get(self, name: str) -> Optional['SymbolTableNode']:
+    def get(self, name: str) -> 'Optional[SymbolTableNode]':
         for cls in self.mro:
             n = cls.names.get(name)
             if n:
                 return n
         return None
 
-    def get_containing_type_info(self, name: str) -> Optional['TypeInfo']:
+    def get_containing_type_info(self, name: str) -> 'Optional[TypeInfo]':
         for cls in self.mro:
             if name in cls.names:
                 return cls
@@ -2150,8 +2161,8 @@ def __str__(self) -> str:
         return self.dump()
 
     def dump(self,
-             str_conv: 'mypy.strconv.StrConv' = None,
-             type_str_conv: 'mypy.types.TypeStrVisitor' = None) -> str:
+             str_conv: 'Optional[mypy.strconv.StrConv]' = None,
+             type_str_conv: 'Optional[mypy.types.TypeStrVisitor]' = None) -> str:
         """Return a string dump of the contents of the TypeInfo."""
         if not str_conv:
             str_conv = mypy.strconv.StrConv()
@@ -2282,9 +2293,13 @@ class SymbolTableNode:
     # Was this defined by assignment to self attribute?
     implicit = False  # type: bool
 
-    def __init__(self, kind: int, node: Optional[SymbolNode], mod_id: str = None,
-                 typ: 'mypy.types.Type' = None,
-                 module_public: bool = True, normalized: bool = False,
+    def __init__(self,
+                 kind: int,
+                 node: Optional[SymbolNode],
+                 mod_id: Optional[str] = None,
+                 typ: 'Optional[mypy.types.Type]' = None,
+                 module_public: bool = True,
+                 normalized: bool = False,
                  alias_tvars: Optional[List[str]] = None,
                  implicit: bool = False) -> None:
         self.kind = kind

mypy/server/deps.py

@@ -1,6 +1,6 @@
 """Generate fine-grained dependencies for AST nodes."""
 
-from typing import Dict, List, Set
+from typing import Dict, List, Set, Optional
 
 from mypy.checkmember import bind_self
 from mypy.nodes import (
@@ -151,7 +151,7 @@ def visit_call_expr(self, e: CallExpr) -> None:
 
     # Helpers
 
-    def add_dependency(self, trigger: str, target: str = None) -> None:
+    def add_dependency(self, trigger: str, target: Optional[str] = None) -> None:
         if target is None:
             target = self.current()
         self.map.setdefault(trigger, set()).add(target)