-:mod:`!ast` --- Abstract Syntax Trees
+:mod:`!ast` --- Abstract syntax trees
=====================================
.. module:: ast
.. _abstract-grammar:
-Abstract Grammar
+Abstract grammar
----------------
The abstract grammar is currently defined as follows:
of :class:`ast.operator`, :class:`ast.unaryop`, :class:`ast.cmpop`,
:class:`ast.boolop` and :class:`ast.expr_context`) on the returned tree
will be singletons. Changes to one will be reflected in all other
- occurrences of the same value (e.g. :class:`ast.Add`).
+ occurrences of the same value (for example, :class:`ast.Add`).
-:mod:`ast` Helpers
+:mod:`ast` helpers
------------------
Apart from the node classes, the :mod:`ast` module defines these utility functions
.. _ast-compiler-flags:
-Compiler Flags
+Compiler flags
--------------
The following flags may be passed to :func:`compile` in order to change
.. _ast-cli:
-Command-Line Usage
+Command-line usage
------------------
.. versionadded:: 3.9
Indentation of nodes in AST (number of spaces).
+.. option:: --feature-version <version>
+
+ Python version in the format 3.x (for example, 3.10). Defaults to the
+ current version of the interpreter.
+
+ .. versionadded:: next
+
+.. option:: -O <level>
+ --optimize <level>
+
+ Optimization level for parser. Defaults to no optimization.
+
+ .. versionadded:: next
+
+.. option:: --show-empty
+
+ Show empty lists and fields that are ``None``. Defaults to not showing empty
+ objects.
+
+ .. versionadded:: next
+
+
If :file:`infile` is specified its contents are parsed to AST and dumped
to stdout. Otherwise, the content is read from stdin.
that the root node type is appropriate.
(Contributed by Irit Katriel in :gh:`130139`.)
+* Add new ``--feature-version``, ``--optimize``, ``--show-empty`` options to
+ command-line interface.
+ (Contributed by Semyon Moroz in :gh:`133367`.)
+
+
bdb
---
'column offsets')
parser.add_argument('-i', '--indent', type=int, default=3,
help='indentation of nodes (number of spaces)')
+ parser.add_argument('--feature-version',
+ type=str, default=None, metavar='VERSION',
+ help='Python version in the format 3.x '
+ '(for example, 3.10)')
+ parser.add_argument('-O', '--optimize',
+ type=int, default=-1, metavar='LEVEL',
+ help='optimization level for parser (default -1)')
+ parser.add_argument('--show-empty', default=False, action='store_true',
+ help='show empty lists and fields in dump output')
args = parser.parse_args(args)
if args.infile == '-':
name = args.infile
with open(args.infile, 'rb') as infile:
source = infile.read()
- tree = parse(source, name, args.mode, type_comments=args.no_type_comments)
- print(dump(tree, include_attributes=args.include_attributes, indent=args.indent))
+
+ # Process feature_version
+ feature_version = None
+ if args.feature_version:
+ try:
+ major, minor = map(int, args.feature_version.split('.', 1))
+ except ValueError:
+ parser.error('Invalid format for --feature-version; '
+ 'expected format 3.x (for example, 3.10)')
+
+ feature_version = (major, minor)
+
+ tree = parse(source, name, args.mode, type_comments=args.no_type_comments,
+ feature_version=feature_version, optimize=args.optimize)
+ print(dump(tree, include_attributes=args.include_attributes,
+ indent=args.indent, show_empty=args.show_empty))
if __name__ == '__main__':
main()
('--no-type-comments', '--no-type-comments'),
('-a', '--include-attributes'),
('-i=4', '--indent=4'),
+ ('--feature-version=3.13', '--feature-version=3.13'),
+ ('-O=-1', '--optimize=-1'),
+ ('--show-empty', '--show-empty'),
)
self.set_source('''
print(1, 2, 3)
self.check_output(source, expect, flag)
def test_indent_flag(self):
- # test 'python -m ast -i/--indent'
+ # test 'python -m ast -i/--indent 0'
source = 'pass'
expect = '''
Module(
with self.subTest(flag=flag):
self.check_output(source, expect, flag)
+ def test_feature_version_flag(self):
+ # test 'python -m ast --feature-version 3.9/3.10'
+ source = '''
+ match x:
+ case 1:
+ pass
+ '''
+ expect = '''
+ Module(
+ body=[
+ Match(
+ subject=Name(id='x', ctx=Load()),
+ cases=[
+ match_case(
+ pattern=MatchValue(
+ value=Constant(value=1)),
+ body=[
+ Pass()])])])
+ '''
+ self.check_output(source, expect, '--feature-version=3.10')
+ with self.assertRaises(SyntaxError):
+ self.invoke_ast('--feature-version=3.9')
+
+ def test_no_optimize_flag(self):
+ # test 'python -m ast -O/--optimize -1/0'
+ source = '''
+ match a:
+ case 1+2j:
+ pass
+ '''
+ expect = '''
+ Module(
+ body=[
+ Match(
+ subject=Name(id='a', ctx=Load()),
+ cases=[
+ match_case(
+ pattern=MatchValue(
+ value=BinOp(
+ left=Constant(value=1),
+ op=Add(),
+ right=Constant(value=2j))),
+ body=[
+ Pass()])])])
+ '''
+ for flag in ('-O=-1', '--optimize=-1', '-O=0', '--optimize=0'):
+ with self.subTest(flag=flag):
+ self.check_output(source, expect, flag)
+
+ def test_optimize_flag(self):
+ # test 'python -m ast -O/--optimize 1/2'
+ source = '''
+ match a:
+ case 1+2j:
+ pass
+ '''
+ expect = '''
+ Module(
+ body=[
+ Match(
+ subject=Name(id='a', ctx=Load()),
+ cases=[
+ match_case(
+ pattern=MatchValue(
+ value=Constant(value=(1+2j))),
+ body=[
+ Pass()])])])
+ '''
+ for flag in ('-O=1', '--optimize=1', '-O=2', '--optimize=2'):
+ with self.subTest(flag=flag):
+ self.check_output(source, expect, flag)
+
+ def test_show_empty_flag(self):
+ # test 'python -m ast --show-empty'
+ source = 'print(1, 2, 3)'
+ expect = '''
+ Module(
+ body=[
+ Expr(
+ value=Call(
+ func=Name(id='print', ctx=Load()),
+ args=[
+ Constant(value=1),
+ Constant(value=2),
+ Constant(value=3)],
+ keywords=[]))],
+ type_ignores=[])
+ '''
+ self.check_output(source, expect, '--show-empty')
+
class ASTOptimiziationTests(unittest.TestCase):
def wrap_expr(self, expr):
--- /dev/null
+Add the ``--feature-version``, ``--optimize``, and ``--show-empty`` options
+to the :mod:`ast` command-line interface. Patch by Semyon Moroz.
projects / thirdparty / Python / cpython.git / commitdiff
