python ast parsing file

Author: Madoshakalaka

py_to_ast_json.py

@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+import argparse
+import ast
+import json
+from _ast import AST
+from pathlib import Path
+
+
+def print_parsed_result(file: Path, out:Path):
+    node = ast.parse(file.read_text())
+
+    json_out = ast2json(node)
+
+#    with open(Path(file.stem + "_ast").with_suffix(".json"), "w") as f:
+#        json.dump(json.loads(json_out), f, indent=2)
+
+    with open(Path(out), "w") as f:
+        json.dump(json.loads(json_out), f, indent=2)
+
+
+def ast2json(node) -> str:
+    if not isinstance(node, AST):
+        raise TypeError('expected AST, got %r' % node.__class__.__name__)
+
+    def _format(node) -> str:
+        if isinstance(node, AST):
+            name = node.__class__.__name__
+            fields = [('_PyType', _format(name))]
+            fields += [(a, _format(b)) for a, b in iter_fields(node)]
+            return '{ %s }' % ', '.join(('"%s": %s' % field for field in fields))
+
+        if isinstance(node, list):
+            return '[ %s ]' % ', '.join([_format(x) for x in node])
+
+        # todo: better handling here?
+        #   this doesn't distinguish between
+        #       some_name: Tuple[a, ...] and some_name: Tuple[a, "..."]
+        #   both are serialized to
+        #                   {
+        #                   "_PyType": "Constant",
+        #                   "value": "...",
+        #                   "kind": null
+        #                 }
+        if node is ...:
+            return json.dumps("...")
+
+        return json.dumps(node)
+
+    return _format(node)
+
+
+def iter_fields(node):
+    for field in node._fields:
+        try:
+            yield field, getattr(node, field)
+        except AttributeError:
+            pass
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser()
+    parser.add_argument("py_file")
+    parser.add_argument("json_dump_file")
+
+    args = parser.parse_args()
+
+    print_parsed_result(Path(args.py_file), Path(args.json_dump_file))