Issue #18192: Introduce importlib.util.MAGIC_NUMBER and document the

deprecation of imp.get_magic().
This commit is contained in:
Brett Cannon 2013-06-14 19:02:34 -04:00
parent 4d7056258b
commit 05a647deed
8 changed files with 37 additions and 8 deletions

View File

@ -21,6 +21,9 @@ This module provides an interface to the mechanisms used to implement the
Return the magic string value used to recognize byte-compiled code files
(:file:`.pyc` files). (This value may be different for each Python version.)
.. deprecated:: 3.4
Use :attr:`importlib.util.MAGIC_NUMBER` instead.
.. function:: get_suffixes()

View File

@ -879,6 +879,13 @@ find and load modules.
This module contains the various objects that help in the construction of
an :term:`importer`.
.. attribute:: MAGIC_NUMBER
The bytes which represent the bytecode version number. If you need help with
loading/writing bytecode then consider :class:`importlib.abc.SourceLoader`.
.. versionadded:: 3.4
.. function:: resolve_name(name, package)
Resolve a relative module name to an absolute one.

View File

@ -23,6 +23,7 @@ from importlib._bootstrap import cache_from_source, source_from_cache
from importlib import _bootstrap
from importlib import machinery
from importlib import util
import importlib
import os
import sys
@ -44,8 +45,11 @@ IMP_HOOK = 9
def get_magic():
"""Return the magic number for .pyc or .pyo files."""
return _bootstrap._MAGIC_BYTES
"""**DEPRECATED**
Return the magic number for .pyc or .pyo files.
"""
return util.MAGIC_NUMBER
def get_tag():

View File

@ -383,8 +383,8 @@ def _call_with_frames_removed(f, *args, **kwds):
# longer be understood by older implementations of the eval loop (usually
# due to the addition of new opcodes).
_MAGIC_BYTES = (3280).to_bytes(2, 'little') + b'\r\n'
_RAW_MAGIC_NUMBER = int.from_bytes(_MAGIC_BYTES, 'little') # For import.c
MAGIC_NUMBER = (3280).to_bytes(2, 'little') + b'\r\n'
_RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c
_PYCACHE = '__pycache__'
@ -663,7 +663,7 @@ def _validate_bytecode_header(data, source_stats=None, name=None, path=None):
magic = data[:4]
raw_timestamp = data[4:8]
raw_size = data[8:12]
if magic != _MAGIC_BYTES:
if magic != MAGIC_NUMBER:
message = 'bad magic number in {!r}: {!r}'.format(name, magic)
_verbose_message(message)
raise ImportError(message, **exc_details)
@ -711,7 +711,7 @@ def _compile_bytecode(data, name=None, bytecode_path=None, source_path=None):
def _code_to_bytecode(code, mtime=0, source_size=0):
"""Compile a code object into bytecode for writing out to a byte-compiled
file."""
data = bytearray(_MAGIC_BYTES)
data = bytearray(MAGIC_NUMBER)
data.extend(_w_long(mtime))
data.extend(_w_long(source_size))
data.extend(marshal.dumps(code))

View File

@ -1,5 +1,6 @@
"""Utility code for constructing importers, etc."""
from ._bootstrap import MAGIC_NUMBER
from ._bootstrap import module_to_load
from ._bootstrap import set_loader
from ._bootstrap import set_package

View File

@ -313,5 +313,16 @@ class ResolveNameTests(unittest.TestCase):
util.resolve_name('..bacon', 'spam')
class MagicNumberTests(unittest.TestCase):
def test_length(self):
# Should be 4 bytes.
self.assertEqual(len(util.MAGIC_NUMBER), 4)
def test_incorporates_rn(self):
# The magic number uses \r\n to come out wrong when splitting on lines.
self.assertTrue(util.MAGIC_NUMBER.endswith(b'\r\n'))
if __name__ == '__main__':
unittest.main()

View File

@ -123,6 +123,9 @@ Core and Builtins
Library
-------
- Issue #18192: Introduce importlib.util.MAGIC_NUMBER and document as deprecated
imp.get_magic().
- Issue #18149: Add filecmp.clear_cache() to manually clear the filecmp cache.
Patch by Mark Levitt

View File

@ -1273,8 +1273,8 @@ const unsigned char _Py_M__importlib[] = {
0,98,121,116,101,99,111,100,101,32,105,115,32,115,116,97,
108,101,32,102,111,114,32,123,33,114,125,244,4,0,0,0,
115,105,122,101,108,3,0,0,0,255,127,255,127,3,0,40,
9,0,0,0,244,12,0,0,0,95,77,65,71,73,67,95,
66,89,84,69,83,114,46,0,0,0,114,140,0,0,0,114,
9,0,0,0,244,12,0,0,0,77,65,71,73,67,95,78,
85,77,66,69,82,114,46,0,0,0,114,140,0,0,0,114,
156,0,0,0,114,31,0,0,0,244,8,0,0,0,69,79,
70,69,114,114,111,114,114,14,0,0,0,114,93,0,0,0,
114,19,0,0,0,40,11,0,0,0,114,52,0,0,0,114,