| # Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html |
| # For details: https://github.com/pylint-dev/pylint/blob/main/LICENSE |
| # Copyright (c) https://github.com/pylint-dev/pylint/blob/main/CONTRIBUTORS.txt |
| |
| """Looks for try/except statements with too much code in the try clause.""" |
| |
| from __future__ import annotations |
| |
| from typing import TYPE_CHECKING |
| |
| from astroid import nodes |
| |
| from pylint import checkers |
| from pylint.checkers import utils |
| from pylint.interfaces import HIGH |
| |
| if TYPE_CHECKING: |
| from pylint.lint import PyLinter |
| |
| |
| class ConsiderRefactorIntoWhileConditionChecker(checkers.BaseChecker): |
| """Checks for instances where while loops are implemented with a constant condition |
| which. |
| |
| always evaluates to truthy and the first statement(s) is/are if statements which, when |
| evaluated. |
| |
| to True, breaks out of the loop. |
| |
| The if statement(s) can be refactored into the while loop. |
| """ |
| |
| name = "consider_refactoring_into_while" |
| msgs = { |
| "R3501": ( |
| "Consider using 'while %s' instead of 'while %s:' an 'if', and a 'break'", |
| "consider-refactoring-into-while-condition", |
| "Emitted when `while True:` loop is used and the first statement is a break condition. " |
| "The ``if / break`` construct can be removed if the check is inverted and moved to " |
| "the ``while`` statement.", |
| ), |
| } |
| |
| @utils.only_required_for_messages("consider-refactoring-into-while-condition") |
| def visit_while(self, node: nodes.While) -> None: |
| self._check_breaking_after_while_true(node) |
| |
| def _check_breaking_after_while_true(self, node: nodes.While) -> None: |
| """Check that any loop with an ``if`` clause has a break statement.""" |
| if not isinstance(node.test, nodes.Const) or not node.test.bool_value(): |
| return |
| pri_candidates: list[nodes.If] = [] |
| for n in node.body: |
| if not isinstance(n, nodes.If): |
| break |
| pri_candidates.append(n) |
| candidates = [] |
| tainted = False |
| for c in pri_candidates: |
| if tainted or not isinstance(c.body[0], nodes.Break): |
| break |
| candidates.append(c) |
| orelse = c.orelse |
| while orelse: |
| orelse_node = orelse[0] |
| if not isinstance(orelse_node, nodes.If): |
| tainted = True |
| else: |
| candidates.append(orelse_node) |
| if not isinstance(orelse_node, nodes.If): |
| break |
| orelse = orelse_node.orelse |
| |
| candidates = [n for n in candidates if isinstance(n.body[0], nodes.Break)] |
| msg = " and ".join( |
| [f"({utils.not_condition_as_string(c.test)})" for c in candidates] |
| ) |
| if len(candidates) == 1: |
| msg = utils.not_condition_as_string(candidates[0].test) |
| if not msg: |
| return |
| |
| self.add_message( |
| "consider-refactoring-into-while-condition", |
| node=node, |
| line=node.lineno, |
| args=(msg, node.test.as_string()), |
| confidence=HIGH, |
| ) |
| |
| |
| def register(linter: PyLinter) -> None: |
| linter.register_checker(ConsiderRefactorIntoWhileConditionChecker(linter)) |