Question about the traverse method on v6

[rodolfolottin]

Hi! I'm currently migrating a Python app from Python 3.9 to Python 3.12. However, I'm encountering an issue while attempting to port the following code:

for query in queries:
    for node in pglast.node.Node(pglast.parser.parse_sql(query)[0]).traverse():
        if isinstance(node, pglast.node.Scalar):
            continue

Specifically, I'm unable to determine how to traverse the query, generate AST nodes and iterate over each element. Has this functionality been included in the latest version?

[lelit]

The functionality has been reimplemented with the visitor pattern:

from pglast import parse_sql
from pglast.visitors import Visitor


class VerboseVisitor(Visitor):
    def visit(self, ancestors, node):
        print("node:", type(node).__name__,
              "ancestor:", type(ancestors.node).__name__)


vv = VerboseVisitor()
vv(parse_sql('select foo from bar'))

Unfortunately I notice that the related doc page comes out empty 😭

Will check.

[lelit]

In the meantime, you can read the v4 visitors page, nothing [substantial] changed between v4 and v6, AFAICT.

[lelit]

I fixed the build on rtd.org, see the v6 visitors page.
Let me know if you need further help.

[rodolfolottin]

Thank you very much!