Checking docstrings with an `ast.NodeVisitor`

[BalzaniEdoardo]

Currently, in order to check all docstrings a AST tree is traversed fully and for each node we are trying to extract the docstrings. This may result in a lot of unnecessary node visits that can be avoided using an ast.NodeVisitor targeting specific nodes. With a visitor one can target nodes which have docstrings:

import ast

class DocstringVisitor(ast.NodeVisitor):
    def __init__(self, path):
        # store what is not passing checks
        self.path = path
        self.links = []
        self.backticks = []

    def check_docstring(self, node, name):
        doc = ast.get_docstring(node)
        # check logic

    def visit_FunctionDef(self, node):
        self.check_docstring(node, node.name)
        self.generic_visit(node)  # remove this line if only top-level docstrings needed 

    def visit_AsyncFunctionDef(self, node):
        self.check_docstring(node, node.name)
        self.generic_visit(node) # remove this line if only top-level docstrings needed

    def visit_ClassDef(self, node):
        self.check_docstring(node, node.name)
        self.generic_visit(node)  # keep, so that methods are also processed

if __name__ == "__main__":
    with open(path) as f:
                tree = ast.parse(f.read(), filename=str(path))
    visitor = DocstringVisitor(path)
    visitor.visit(tree)
    print(visitor.links)
    print(visitor.backticks)