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Add tests and docs, change output.
  • Loading branch information
serhiy-storchaka committed Sep 8, 2023
commit 9e575aa5be1660df0b63ac863422c4ffafeaeef6
18 changes: 18 additions & 0 deletions Doc/library/symtable.rst
Original file line number Diff line number Diff line change
Expand Up @@ -197,3 +197,21 @@ Examining Symbol Tables

Return the namespace bound to this name. If more than one or no namespace
is bound to this name, a :exc:`ValueError` is raised.


.. _symtable-cli:

Command-Line Usage
------------------

.. versionadded:: 3.13

The :mod:`symtable` module can be executed as a script from the command line.

.. code-block:: sh

python -m symtable [infile...]

Symbol tables are generated for the specified Python source files and
dumped to stdout.
If no input file is specified, the content is read from stdin.
63 changes: 35 additions & 28 deletions Lib/symtable.py
Original file line number Diff line number Diff line change
Expand Up @@ -226,17 +226,14 @@ def __init__(self, name, flags, namespaces=None, *, module_scope=False):
self.__module_scope = module_scope

def __repr__(self):
flags_repr = [_scopes_value_to_name.get(self.__scope, str(self.__scope))]
for flagname, flagvalue in _flags.items():
if self.__flags & flagvalue:
flags_repr.append(flagname)
return "<symbol {!r} {}>".format(self.__name, ', '.join(flags_repr))
flags_str = '|'.join(self._flags_str())
return f'<symbol {self.__name!r}: {self._scope_str()}, {flags_str}>'

def _scope_str(self):
return _scopes_value_to_name[self.__scope]
return _scopes_value_to_name.get(self.__scope) or str(self.__scope)

def _flags_str(self):
for flagname, flagvalue in _flags.items():
for flagname, flagvalue in _flags:
if self.__flags & flagvalue == flagvalue:
yield flagname

Expand Down Expand Up @@ -328,33 +325,43 @@ def get_namespace(self):
else:
return self.__namespaces[0]

_flags = {'USE': USE}
_flags.update(kv for kv in globals().items() if kv[0].startswith('DEF_'))

_flags = [('USE', USE)]
_flags.extend(kv for kv in globals().items() if kv[0].startswith('DEF_'))
_scopes_names = ('FREE', 'LOCAL', 'GLOBAL_IMPLICIT', 'GLOBAL_EXPLICIT', 'CELL')
_scopes_name_to_value = {n: globals()[n] for n in _scopes_names}
_scopes_value_to_name = {v: k for k, v in _scopes_name_to_value.items()}
_scopes_value_to_name = {globals()[n]: n for n in _scopes_names}


if __name__ == "__main__":
def main(args):
import sys

def print_symbols(table, level=0):
indent = ' ' * level
nested = "nested " if table.is_nested() else ""
if table.get_type() == 'module':
what = f'from file {table._filename!r}'
else:
what = f'{table.get_name()!r}'
print(f'{indent}symbol table for {nested}{table.get_type()} {what}:')
for ident in table.get_identifiers():
info = table.lookup(ident)
flags = ', '.join(info._flags_str()).lower()
print(f'{indent}{info._scope_str().lower()} symbol {info.get_name()!r}: {flags}')
for table2 in info.get_namespaces():
print_symbols(table2, level + 1)
print()

if len(sys.argv) > 1:
for filename in sys.argv[1:]:
symbol = table.lookup(ident)
flags = ', '.join(symbol._flags_str()).lower()
print(f' {indent}{symbol._scope_str().lower()} symbol {symbol.get_name()!r}: {flags}')
print()

for table2 in table.get_children():
print_symbols(table2, level + 1)

for filename in args or ['-']:
if filename == '-':
src = sys.stdin.read()
filename = '<stdin>'
else:
with open(filename, 'rb') as f:
src = f.read()
mod = symtable(src, filename, 'exec')
print_symbols(mod)
else:
src = sys.stdin.read()
mod = symtable(src, '<stdin>', 'exec')
print_symbols(mod)
mod = symtable(src, filename, 'exec')
print_symbols(mod)


if __name__ == "__main__":
import sys
main(sys.argv[1:])
54 changes: 54 additions & 0 deletions Lib/test/test_symtable.py
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,8 @@
import symtable
import unittest

from test import support
from test.support import os_helper


TEST_CODE = """
Expand Down Expand Up @@ -251,6 +253,58 @@ def test_symtable_repr(self):
self.assertEqual(str(self.top), "<SymbolTable for module ?>")
self.assertEqual(str(self.spam), "<Function SymbolTable for spam in ?>")

def test_symbol_repr(self):
self.assertEqual(repr(self.spam.lookup("glob")),
"<symbol 'glob': GLOBAL_IMPLICIT, USE>")
self.assertEqual(repr(self.spam.lookup("bar")),
"<symbol 'bar': GLOBAL_EXPLICIT, DEF_GLOBAL|DEF_LOCAL>")
self.assertEqual(repr(self.spam.lookup("a")),
"<symbol 'a': LOCAL, DEF_PARAM>")
self.assertEqual(repr(self.spam.lookup("internal")),
"<symbol 'internal': LOCAL, USE|DEF_LOCAL>")
self.assertEqual(repr(self.spam.lookup("other_internal")),
"<symbol 'other_internal': LOCAL, DEF_LOCAL>")
self.assertEqual(repr(self.internal.lookup("x")),
"<symbol 'x': FREE, USE>")
self.assertEqual(repr(self.other_internal.lookup("some_var")),
"<symbol 'some_var': FREE, USE|DEF_NONLOCAL|DEF_LOCAL>")


class CommandLineTest(unittest.TestCase):
maxDiff = None

def test_file(self):
filename = os_helper.TESTFN
self.addCleanup(os_helper.unlink, filename)
with open(filename, 'w') as f:
f.write(TEST_CODE)
with support.captured_stdout() as stdout:
symtable.main([filename])
out = stdout.getvalue()
self.assertIn('\n\n', out)
self.assertNotIn('\n\n\n', out)
lines = out.splitlines()
self.assertIn(f"symbol table for module from file {filename!r}:", lines)
self.assertIn(" local symbol 'glob': def_local", lines)
self.assertIn(" global_implicit symbol 'glob': use", lines)
self.assertIn(" local symbol 'spam': def_local", lines)
self.assertIn(" symbol table for function 'spam':", lines)

def test_stdin(self):
with support.captured_stdin() as stdin:
stdin.write(TEST_CODE)
stdin.seek(0)
with support.captured_stdout() as stdout:
symtable.main([])
out = stdout.getvalue()
stdin.seek(0)
with support.captured_stdout() as stdout:
symtable.main(['-'])
self.assertEqual(stdout.getvalue(), out)
lines = out.splitlines()
print(out)
self.assertIn("symbol table for module from file '<stdin>':", lines)


if __name__ == '__main__':
unittest.main()
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Implement the CLI of the :mod:`symtable` module and improve the repr of
:class:`~symtable.Symbol`.