eric: eric6/Plugins/CheckerPlugins/CodeStyleChecker/Simplify/SimplifyNodeVisitor.py@b5903eaa7a7b (annotated)

 # -*- coding: utf-8 -*-
 # Copyright (c) 2021 Detlev Offenbach <detlev@die-offenbachs.de>
 #
 """
 Module implementing a node visitor checking for code that could be simplified.
 """
 import ast
 import collections
 import copy
 import itertools
 try:
     from ast import unparse
 except ImportError:
     # Python < 3.9
     from .ast_unparse import unparse
 ######################################################################
 ## The following code is derived from the flake8-simplify package.
 ##
 ## Original License:
 ##
 ## MIT License
 ##
 ## Copyright (c) 2020 Martin Thoma
 ##
 ## Permission is hereby granted, free of charge, to any person obtaining a copy
 ## of this software and associated documentation files (the "Software"), to
 ## deal in the Software without restriction, including without limitation the
 ## rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 ## sell copies of the Software, and to permit persons to whom the Software is
 ## furnished to do so, subject to the following conditions:
 ##
 ## The above copyright notice and this permission notice shall be included in
 ## all copies or substantial portions of the Software.
 ##
 ## THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 ## IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 ## FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 ## AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 ## LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 ## FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 ## IN THE SOFTWARE.
 ######################################################################
 BOOL_CONST_TYPES = (ast.Constant, ast.NameConstant)
 AST_CONST_TYPES = (ast.Constant, ast.NameConstant, ast.Str, ast.Num)
 STR_TYPES = (ast.Constant, ast.Str)
 class SimplifyNodeVisitor(ast.NodeVisitor):
     """
     Class to traverse the AST node tree and check for code that can be
     simplified.
     """
     def __init__(self, errorCallback):
         """
         Constructor
         @param errorCallback callback function to register an error
         @type func
         """
         super(SimplifyNodeVisitor, self).__init__()
         self.__error = errorCallback
         self.__classDefinitionStack = []
     def visit_Expr(self, node):
         """
         Public method to process an Expr node.
         @param node reference to the Expr node
         @type ast.Expr
         """
         self.__check112(node)
         self.generic_visit(node)
     def visit_Assign(self, node):
         """
         Public method to process an Assign node.
         @param node reference to the Assign node
         @type ast.Assign
         """
         self.__check181(node)
         self.generic_visit(node)
     def visit_BoolOp(self, node):
         """
         Public method to process a BoolOp node.
         @param node reference to the BoolOp node
         @type ast.BoolOp
         """
         self.__check101(node)
         self.__check109(node)
         self.__check221(node)
         self.__check222(node)
         self.__check223(node)
         self.__check224(node)
         self.generic_visit(node)
     def visit_If(self, node):
         """
         Public method to process an If node.
         @param node reference to the If node
         @type ast.If
         """
         self.__check102(node)
         self.__check103(node)
         self.__check106(node)
         self.__check108(node)
         self.__check114(node)
         self.__check116(node)
         self.generic_visit(node)
     def visit_IfExp(self, node):
         """
         Public method to process an IfExp node.
         @param node reference to the IfExp node
         @type ast.IfExp
         """
         self.__check211(node)
         self.__check212(node)
         self.__check213(node)
         self.generic_visit(node)
     def visit_For(self, node):
         """
         Public method to process a For node.
         @param node reference to the For node
         @type ast.For
         """
         self.__check104(node)
         self.__check110_111(node)
         self.__check113(node)
         self.__check118(node)
         self.generic_visit(node)
     def visit_Try(self, node):
         """
         Public method to process a Try node.
         @param node reference to the Try node
         @type ast.Try
         """
         self.__check105(node)
         self.__check107(node)
         self.generic_visit(node)
     def visit_Call(self, node):
         """
         Public method to process a Call node.
         @param node reference to the Call node
         @type ast.Call
         """
         self.__check115(node)
         self.__check182(node)
         self.generic_visit(node)
     def visit_With(self, node):
         """
         Public method to process a With node.
         @param node reference to the With node
         @type ast.With
         """
         self.__check117(node)
         self.generic_visit(node)
     def visit_Compare(self, node):
         """
         Public method to process a Compare node.
         @param node reference to the Compare node
         @type ast.Compare
         """
         self.__check118(node)
         self.__check301(node)
         self.generic_visit(node)
     def visit_ClassDef(self, node):
         """
         Public method to process a ClassDef node.
         @param node reference to the ClassDef node
         @type ast.ClassDef
         """
         # register the name of the class being defined
         self.__classDefinitionStack.append(node.name)
         self.__check119(node)
         self.__check120(node)
         self.generic_visit(node)
         self.__classDefinitionStack.pop()
     def visit_UnaryOp(self, node):
         """
         Public method to process a UnaryOp node.
         @param node reference to the UnaryOp node
         @type ast.UnaryOp
         """
         self.__check201(node)
         self.__check202(node)
         self.__check203(node)
         self.__check204(node)
         self.__check205(node)
         self.__check206(node)
         self.__check207(node)
         self.__check208(node)
         self.generic_visit(node)
     #############################################################
     ## Helper methods for the various checkers below
     #############################################################
     def __getDuplicatedIsinstanceCall(self, node):
         """
         Private method to get a list of isinstance arguments which could
         be combined.
         @param node reference to the AST node to be inspected
         @type ast.BoolOp
         @return list of variable names of duplicated isinstance calls
         @rtype list of str
         """
         counter = collections.defaultdict(int)
         for call in node.values:
             # Ensure this is a call of the built-in isinstance() function.
             if not isinstance(call, ast.Call) or len(call.args) != 2:
                 continue
             functionName = unparse(call.func)
             if functionName != "isinstance":
                 continue
             arg0Name = unparse(call.args[0])
             counter[arg0Name] += 1
         return [name for name, count in counter.items() if count > 1]
     def __isConstantIncrease(self, expression):
         """
         Private method check the given expression for being a constant
         increase.
         @param expression reference to the expression node
         @type ast.AugAssign
         @return flag indicating a constant increase
         @rtype bool
         """
         return (
             isinstance(expression.op, ast.Add) and
             isinstance(expression.value, (ast.Constant, ast.Num))
         )
     def __getIfBodyPairs(self, node):
         """
         Private method to extract a list of pairs of test and body for an
         If node.
         @param node reference to the If node to be processed
         @type ast.If
         @return list of pairs of test and body
         @rtype list of tuples of (ast.expr, [ast.stmt])
         """
         pairs = [(node.test, node.body)]
         orelse = node.orelse
         while (
             isinstance(orelse, list) and
             len(orelse) == 1 and
             isinstance(orelse[0], ast.If)
         ):
             pairs.append((orelse[0].test, orelse[0].body))
             orelse = orelse[0].orelse
         return pairs
     def __isSameBody(self, body1, body2):
         """
         Private method check, if the given bodies are equivalent.
         @param body1 list of statements of the first body
         @type list of ast.stmt
         @param body2 list of statements of the second body
         @type list of ast.stmt
         @return flag indicating identical bodies
         @rtype bool
         """
         if len(body1) != len(body2):
             return False
         for a, b in zip(body1, body2):
             try:
                 statementEqual = self.__isStatementEqual(a, b)
             except RecursionError:  # maximum recursion depth
                 statementEqual = False
             if not statementEqual:
                 return False
         return True
     def __isSameExpression(self, a, b):
         """
         Private method to check, if two expressions are equal.
         @param a first expression to be checked
         @type ast.expr
         @param b second expression to be checked
         @type ast.expr
         @return flag indicating equal expressions
         @rtype bool
         """
         if isinstance(a, ast.Name) and isinstance(b, ast.Name):
             return a.id == b.id
         else:
             return False
     def __isStatementEqual(self, a, b):
         """
         Private method to check, if two statements are equal.
         @param a reference to the first statement
         @type ast.stmt
         @param b reference to the second statement
         @type ast.stmt
         @return flag indicating if the two statements are equal
         @rtype bool
         """
         if type(a) is not type(b):
             return False
         if isinstance(a, ast.AST):
             for k, v in vars(a).items():
                 if k in ("lineno", "col_offset", "ctx", "end_lineno",
                          "parent"):
                     continue
                 if not self.__isStatementEqual(v, getattr(b, k)):
                     return False
             return True
         elif isinstance(a, list):
             return all(itertools.starmap(self.__isStatementEqual, zip(a, b)))
         else:
             return a == b
     def __isExceptionCheck(self, node):
         """
         Private method to check, if the node is checking an exception.
         @param node reference to the node to be checked
         @type ast.If
         @return flag indicating an exception check
         @rtype bool
         """
         return (
             len(node.body) == 1 and isinstance(node.body[0], ast.Raise)
         )
     def __negateTest(self, node):
         """
         Private method negate the given Compare node.
         @param node reference to the node to be negated
         @type ast.Compare
         @return node with negated logic
         @rtype ast.Compare
         """
         newNode = copy.deepcopy(node)
         op = newNode.ops[0]
         if isinstance(op, ast.Eq):
             op = ast.NotEq()
         elif isinstance(op, ast.NotEq):
             op = ast.Eq()
         elif isinstance(op, ast.Lt):
             op = ast.GtE()
         elif isinstance(op, ast.LtE):
             op = ast.Gt()
         elif isinstance(op, ast.Gt):
             op = ast.LtE()
         elif isinstance(op, ast.GtE):
             op = ast.Lt()
         elif isinstance(op, ast.Is):
             op = ast.IsNot()
         elif isinstance(op, ast.IsNot):
             op = ast.Is()
         elif isinstance(op, ast.In):
             op = ast.NotIn()
         elif isinstance(op, ast.NotIn):
             op = ast.In()
         newNode.ops = [op]
         return newNode
     #############################################################
     ## Methods to check for possible code simplifications below
     #############################################################
     def __check101(self, node):
         """
         Private method to check for duplicate isinstance() calls.
         @param node reference to the AST node to be checked
         @type ast.BoolOp
         """
         if isinstance(node.op, ast.Or):
             for variable in self.__getDuplicatedIsinstanceCall(node):
                 self.__error(node.lineno - 1, node.col_offset, "Y101",
                              variable)
     def __check102(self, node):
         """
         Private method to check for nested if statements without else blocks.
         @param node reference to the AST node to be checked
         @type ast.If
         """
         # ## Pattern 1
         # if a: <---
         #     if b: <---
         #         c
         isPattern1 = (
             node.orelse == [] and
             len(node.body) == 1 and
             isinstance(node.body[0], ast.If) and
             node.body[0].orelse == []
         )
         # ## Pattern 2
         # if a: < irrelvant for here
         #     pass
         # elif b:  <--- this is treated like a nested block
         #     if c: <---
         #         d
         if isPattern1:
             self.__error(node.lineno - 1, node.col_offset, "Y102")
     def __check103(self, node):
         """
         Private method to check for calls that wrap a condition to return
         a bool.
         @param node reference to the AST node to be checked
         @type ast.If
         """
         # if cond:
         #     return True
         # else:
         #     return False
         if not (
             len(node.body) != 1 or
             not isinstance(node.body[0], ast.Return) or
             not isinstance(node.body[0].value, BOOL_CONST_TYPES) or
             not (
                 node.body[0].value.value is True or
                 node.body[0].value.value is False
             ) or
             len(node.orelse) != 1 or
             not isinstance(node.orelse[0], ast.Return) or
             not isinstance(node.orelse[0].value, BOOL_CONST_TYPES) or
             not (
                 node.orelse[0].value.value is True or
                 node.orelse[0].value.value is False
             )
         ):
             condition = unparse(node.test)
             self.__error(node.lineno - 1, node.col_offset, "Y103", condition)
     def __check104(self, node):
         """
         Private method to check for "iterate and yield" patterns.
         @param node reference to the AST node to be checked
         @type ast.For
         """
         # for item in iterable:
         #     yield item
         if not (
             len(node.body) != 1 or
             not isinstance(node.body[0], ast.Expr) or
             not isinstance(node.body[0].value, ast.Yield) or
             not isinstance(node.target, ast.Name) or
             not isinstance(node.body[0].value.value, ast.Name) or
             node.target.id != node.body[0].value.value.id or
             node.orelse != []
         ):
             iterable = unparse(node.iter)
             self.__error(node.lineno - 1, node.col_offset, "Y104", iterable)
     def __check105(self, node):
         """
         Private method to check for "try-except-pass" patterns.
         @param node reference to the AST node to be checked
         @type ast.Try
         """
         # try:
         #     foo()
         # except ValueError:
         #     pass
         if not (
             len(node.body) != 1 or
             len(node.handlers) != 1 or
             not isinstance(node.handlers[0], ast.ExceptHandler) or
             len(node.handlers[0].body) != 1 or
             not isinstance(node.handlers[0].body[0], ast.Pass) or
             node.orelse != []
         ):
             if node.handlers[0].type is None:
                 exception = "Exception"
             else:
                 exception = unparse(node.handlers[0].type)
             self.__error(node.lineno - 1, node.col_offset, "Y105", exception)
     def __check106(self, node):
         """
         Private method to check for calls where an exception is raised in else.
         @param node reference to the AST node to be checked
         @type ast.If
         """
         # if cond:
         #     return True
         # else:
         #     raise Exception
         just_one = (
             len(node.body) == 1 and
             len(node.orelse) >= 1 and
             isinstance(node.orelse[-1], ast.Raise) and
             not isinstance(node.body[-1], ast.Raise)
         )
         many = (
             len(node.body) > 2 * len(node.orelse) and
             len(node.orelse) >= 1 and
             isinstance(node.orelse[-1], ast.Raise) and
             not isinstance(node.body[-1], ast.Raise)
         )
         if just_one or many:
             self.__error(node.lineno - 1, node.col_offset, "Y106")
     def __check107(self, node):
         """
         Private method to check for calls where try/except and finally have
         'return'.
         @param node reference to the AST node to be checked
         @type ast.Try
         """
         # def foo():
         #     try:
         #         1 / 0
         #         return "1"
         #     except:
         #         return "2"
         #     finally:
         #         return "3"
         tryHasReturn = False
         for stmt in node.body:
             if isinstance(stmt, ast.Return):
                 tryHasReturn = True
                 break
         exceptHasReturn = False
         for stmt2 in node.handlers:
             if isinstance(stmt2, ast.Return):
                 exceptHasReturn = True
                 break
         finallyHasReturn = False
         finallyReturn = None
         for stmt in node.finalbody:
             if isinstance(stmt, ast.Return):
                 finallyHasReturn = True
                 finallyReturn = stmt
                 break
         if (tryHasReturn or exceptHasReturn) and finallyHasReturn:
             if finallyReturn is not None:
                 self.__error(finallyReturn.lineno - 1,
                              finallyReturn.col_offset, "Y107")
     def __check108(self, node):
         """
         Private method to check for if-elses which could be a ternary
         operator assignment.
         @param node reference to the AST node to be checked
         @type ast.If
         """
         # if a:
         #     b = c
         # else:
         #     b = d
         #
         # but not:
         # if a:
         #     b = c
         # elif c:
         #     b = e
         # else:
         #     b = d
         if (
             len(node.body) == 1 and
             len(node.orelse) == 1 and
             isinstance(node.body[0], ast.Assign) and
             isinstance(node.orelse[0], ast.Assign) and
             len(node.body[0].targets) == 1 and
             len(node.orelse[0].targets) == 1 and
             isinstance(node.body[0].targets[0], ast.Name) and
             isinstance(node.orelse[0].targets[0], ast.Name) and
             node.body[0].targets[0].id == node.orelse[0].targets[0].id and
             not isinstance(node.parent, ast.If)
         ):
             assign = unparse(node.body[0].targets[0])
             body = unparse(node.body[0].value)
             cond = unparse(node.test)
             orelse = unparse(node.orelse[0].value)
             if len(
                 "{0} = {1} if {2} else {3}".format(assign, body, cond, orelse)
             ) < 79:
                 # don't flag an issue, if the ternary would get too complicated
                 self.__error(node.lineno - 1, node.col_offset, "Y108",
                              assign, body, cond, orelse)
     def __check109(self, node):
         """
         Private method to check for multiple equalities with the same value
         are combined via "or".
         @param node reference to the AST node to be checked
         @type ast.BoolOp
         """
         # if a == b or a == c:
         #     d
         if isinstance(node.op, ast.Or):
             equalities = [
                 value
                 for value in node.values
                 if isinstance(value, ast.Compare) and
                 len(value.ops) == 1 and
                 isinstance(value.ops[0], ast.Eq)
             ]
             ids = []  # (name, compared_to)
             for eq in equalities:
                 if isinstance(eq.left, ast.Name):
                     ids.append((eq.left, eq.comparators[0]))
                 if (
                     len(eq.comparators) == 1 and
                     isinstance(eq.comparators[0], ast.Name)
                 ):
                     ids.append((eq.comparators[0], eq.left))
             id2count = {}
             for identifier, comparedTo in ids:
                 if identifier.id not in id2count:
                     id2count[identifier.id] = []
                 id2count[identifier.id].append(comparedTo)
             for value, values in id2count.items():
                 if len(values) == 1:
                     continue
                 self.__error(node.lineno - 1, node.col_offset, "Y109",
                              value, unparse(ast.Tuple(elts=values)),
                              unparse(node))
     def __check110_111(self, node):
         """
         Private method to check if any / all could be used.
         @param node reference to the AST node to be checked
         @type ast.For
         """
         # for x in iterable:
         #     if check(x):
         #         return True
         # return False
         #
         # for x in iterable:
         #     if check(x):
         #         return False
         # return True
         if (
             len(node.body) == 1 and
             isinstance(node.body[0], ast.If) and
             len(node.body[0].body) == 1 and
             isinstance(node.body[0].body[0], ast.Return) and
             isinstance(node.body[0].body[0].value, BOOL_CONST_TYPES) and
             hasattr(node.body[0].body[0].value, "value")
         ):
             check = unparse(node.body[0].test)
             target = unparse(node.target)
             iterable = unparse(node.iter)
             if node.body[0].body[0].value.value is True:
                 self.__error(node.lineno - 1, node.col_offset, "Y110",
                              check, target, iterable)
             elif node.body[0].body[0].value.value is False:
                 check = "not " + check
                 if check.startswith("not not"):
                     check = check[len("not not "):]
                 self.__error(node.lineno - 1, node.col_offset, "Y111",
                              check, target, iterable)
     def __check112(self, node):
         """
         Private method to check for non-capitalized calls to environment
         variables.
         @param node reference to the AST node to be checked
         @type ast.Expr
         """
         # os.environ["foo"]
         # os.environ.get("bar")
         isIndexCall = (
             isinstance(node.value, ast.Subscript) and
             isinstance(node.value.value, ast.Attribute) and
             isinstance(node.value.value.value, ast.Name) and
             node.value.value.value.id == "os" and
             node.value.value.attr == "environ" and
             (
                 (
                     isinstance(node.value.slice, ast.Index) and
                     isinstance(node.value.slice.value, STR_TYPES)
                 ) or
                 isinstance(node.value.slice, ast.Constant)
             )
         )
         if isIndexCall:
             subscript = node.value
             slice_ = subscript.slice
             if isinstance(slice_, ast.Index):
                 # Python < 3.9
                 stringPart = slice_.value  # type: ignore
                 if isinstance(stringPart, ast.Str):
                     envName = stringPart.s  # Python 3.6 / 3.7 fallback
                 else:
                     envName = stringPart.value
             elif isinstance(slice_, ast.Constant):
                 # Python 3.9
                 envName = slice_.value
             # Check if this has a change
             hasChange = envName != envName.upper()
         isGetCall = (
             isinstance(node.value, ast.Call) and
             isinstance(node.value.func, ast.Attribute) and
             isinstance(node.value.func.value, ast.Attribute) and
             isinstance(node.value.func.value.value, ast.Name) and
             node.value.func.value.value.id == "os" and
             node.value.func.value.attr == "environ" and
             node.value.func.attr == "get" and
             len(node.value.args) in [1, 2] and
             isinstance(node.value.args[0], STR_TYPES)
         )
         if isGetCall:
             call = node.value
             stringPart = call.args[0]
             if isinstance(stringPart, ast.Str):
                 envName = stringPart.s  # Python 3.6 / 3.7 fallback
             else:
                 envName = stringPart.value
             # Check if this has a change
             hasChange = envName != envName.upper()
         if not (isIndexCall or isGetCall) or not hasChange:
             return
         if isIndexCall:
             original = unparse(node)
             expected = f"os.environ['{envName.upper()}']"
         elif isGetCall:
             original = unparse(node)
             if len(node.value.args) == 1:
                 expected = f"os.environ.get('{envName.upper()}')"
             else:
                 defaultValue = unparse(node.value.args[1])
                 expected = (
                     f"os.environ.get('{envName.upper()}', '{defaultValue}')"
                 )
         else:
             return
         self.__error(node.lineno - 1, node.col_offset, "Y112", expected,
                      original)
     def __check113(self, node):
         """
         Private method to check for loops in which "enumerate" should be
         used.
         @param node reference to the AST node to be checked
         @type ast.For
         """
         # idx = 0
         # for el in iterable:
         #     ...
         #     idx += 1
         variableCandidates = []
         for expression in node.body:
             if (
                 isinstance(expression, ast.AugAssign) and
                 self.__isConstantIncrease(expression) and
                 isinstance(expression.target, ast.Name)
             ):
                 variableCandidates.append(expression.target)
         for candidate in variableCandidates:
             self.__error(candidate.lineno - 1, candidate.col_offset, "Y113",
                          unparse(candidate))
     def __check114(self, node):
         """
         Private method to check for alternative if clauses with identical
         bodies.
         @param node reference to the AST node to be checked
         @type ast.If
         """
         # if a:
         #     b
         # elif c:
         #     b
         ifBodyPairs = self.__getIfBodyPairs(node)
         errorPairs = []
         for ifbody1, ifbody2 in itertools.combinations(ifBodyPairs, 2):
             if self.__isSameBody(ifbody1[1], ifbody2[1]):
                 errorPairs.append((ifbody1, ifbody2))
         for ifbody1, ifbody2 in errorPairs:
             self.__error(ifbody1[0].lineno - 1, ifbody1[0].col_offset, "Y114",
                          unparse(ifbody1[0]), unparse(ifbody2[0]))
     def __check115(self, node):
         """
         Private method to to check for places where open() is called without
         a context handler.
         @param node reference to the AST node to be checked
         @type ast.Call
         """
         # f = open(...)
         #. ..  # (do something with f)
         # f.close()
         if (
             isinstance(node.func, ast.Name) and
             node.func.id == "open" and
             not isinstance(node.parent, ast.withitem)
         ):
             self.__error(node.lineno - 1, node.col_offset, "Y115")
     def __check116(self, node):
         """
         Private method to check for places with 3 or more consecutive
         if-statements with direct returns.
         * Each if-statement must be a check for equality with the
           same variable
         * Each if-statement must just have a "return"
         * Else must also just have a return
         @param node reference to the AST node to be checked
         @type ast.If
         """
         # if a == "foo":
         #     return "bar"
         # elif a == "bar":
         #     return "baz"
         # elif a == "boo":
         #     return "ooh"
         # else:
         #    return 42
         if (
             isinstance(node.test, ast.Compare) and
             isinstance(node.test.left, ast.Name) and
             len(node.test.ops) == 1 and
             isinstance(node.test.ops[0], ast.Eq) and
             len(node.test.comparators) == 1 and
             isinstance(node.test.comparators[0], AST_CONST_TYPES) and
             len(node.body) == 1 and
             isinstance(node.body[0], ast.Return) and
             len(node.orelse) == 1 and
             isinstance(node.orelse[0], ast.If)
         ):
             variable = node.test.left
             child = node.orelse[0]
             elseValue = None
             if node.body[0].value is not None:
                 bodyValueStr = unparse(node.body[0].value).strip("'")
             else:
                 bodyValueStr = "None"
             if isinstance(node.test.comparators[0], ast.Str):
                 keyValuePairs = {
                     node.test.comparators[0].s: bodyValueStr
                 }
             elif isinstance(node.test.comparators[0], ast.Num):
                 keyValuePairs = {
                     node.test.comparators[0].n: bodyValueStr,
                 }
             else:
                 keyValuePairs = {
                     node.test.comparators[0].value: bodyValueStr
                 }
             while child:
                 if not (
                     isinstance(child.test, ast.Compare) and
                     isinstance(child.test.left, ast.Name) and
                     child.test.left.id == variable.id and
                     len(child.test.ops) == 1 and
                     isinstance(child.test.ops[0], ast.Eq) and
                     len(child.test.comparators) == 1 and
                     isinstance(child.test.comparators[0], AST_CONST_TYPES) and
                     len(child.body) == 1 and
                     isinstance(child.body[0], ast.Return) and
                     len(child.orelse) <= 1
                 ):
                     return
                 if isinstance(child.test.comparators[0], ast.Str):
                     key = child.test.comparators[0].s
                 elif isinstance(child.test.comparators[0], ast.Num):
                     key = child.test.comparators[0].n
                 else:
                     key = child.test.comparators[0].value
                 keyValuePairs[key] = unparse(child.body[0].value).strip("'")
                 if len(child.orelse) == 1:
                     if isinstance(child.orelse[0], ast.If):
                         child = child.orelse[0]
                     elif isinstance(child.orelse[0], ast.Return):
                         elseValue = unparse(child.orelse[0].value)
                         child = None
                     else:
                         return
                 else:
                     child = None
             if len(keyValuePairs) < 3:
                 return
             if elseValue:
                 ret = f"{keyValuePairs}.get({variable.id}, {elseValue})"
             else:
                 ret = f"{keyValuePairs}.get({variable.id})"
             self.__error(node.lineno - 1, node.col_offset, "Y116", ret)
     def __check117(self, node):
         """
         Private method to check for multiple with-statements with same scope.
         @param node reference to the AST node to be checked
         @type ast.With
         """
         # with A() as a:
         #     with B() as b:
         #         print("hello")
         if (
             len(node.body) == 1 and
             isinstance(node.body[0], ast.With)
         ):
             withItems = []
             for withitem in node.items + node.body[0].items:
                 withItems.append(f"{unparse(withitem)}")
             mergedWith = f"with {', '.join(withItems)}:"
             self.__error(node.lineno - 1, node.col_offset, "Y117", mergedWith)
     def __check118(self, node):
         """
         Private method to check for usages of "key in dict.keys()".
         @param node reference to the AST node to be checked
         @type ast.Compare or ast.For
         """
         # Pattern 1:
         #
         # if key in dict.keys():
         #     # do something
         #
         # Pattern 2:
         #
         # for key in dict.keys():
         #     # do something
         if (
             isinstance(node, ast.Compare) and
             len(node.ops) == 1 and
             isinstance(node.ops[0], ast.In) and
             len(node.comparators) == 1
         ):
             callNode = node.comparators[0]
         elif (
             isinstance(node, ast.For)
         ):
             callNode = node.iter
         else:
             callNode = None
         if not isinstance(callNode, ast.Call):
             return
         attrNode = callNode.func
 e1157bd8b4c2
Code Style Checker

Detlev Offenbach <detlev@die-offenbachs.de>
parents: 
8191

Mercurial Repositories > eric / annotate

eric6/Plugins/CheckerPlugins/CodeStyleChecker/Simplify/SimplifyNodeVisitor.py@b5903eaa7a7b (annotated)

eric6/Plugins/CheckerPlugins/CodeStyleChecker/Simplify/SimplifyNodeVisitor.py