Added docstrings.
Added an optional third parameter giving the purported filename for
error messages from the module.
Append a newline to the code string if needed.
diff --git a/Lib/py_compile.py b/Lib/py_compile.py
index 1adc3a2..7d5837c 100644
--- a/Lib/py_compile.py
+++ b/Lib/py_compile.py
@@ -1,37 +1,68 @@
-# Routine to "compile" a .py file to a .pyc file.
-# This has intimate knowledge of how Python/import.c does it.
-# By Sjoerd Mullender (I forced him to write it :-).
+"""Routine to "compile" a .py file to a .pyc (or .pyo) file.
+
+This module has intimate knowledge of the format of .pyc files.
+"""
import imp
MAGIC = imp.get_magic()
def wr_long(f, x):
- f.write(chr( x & 0xff))
- f.write(chr((x >> 8) & 0xff))
- f.write(chr((x >> 16) & 0xff))
- f.write(chr((x >> 24) & 0xff))
+ "Internal; write a 32-bit int to a file in little-endian order."
+ f.write(chr( x & 0xff))
+ f.write(chr((x >> 8) & 0xff))
+ f.write(chr((x >> 16) & 0xff))
+ f.write(chr((x >> 24) & 0xff))
-def compile(file, cfile = None):
- import os, marshal, __builtin__
- f = open(file)
- try:
- timestamp = os.fstat(file.fileno())
- except AttributeError:
- timestamp = long(os.stat(file)[8])
- codestring = f.read()
- f.close()
- codeobject = __builtin__.compile(codestring, file, 'exec')
- if not cfile:
- cfile = file + (__debug__ and 'c' or 'o')
- fc = open(cfile, 'wb')
- fc.write('\0\0\0\0')
- wr_long(fc, timestamp)
- marshal.dump(codeobject, fc)
- fc.flush()
- fc.seek(0, 0)
- fc.write(MAGIC)
- fc.close()
- if os.name == 'mac':
- import macfs
- macfs.FSSpec(cfile).SetCreatorType('Pyth', 'PYC ')
- macfs.FSSpec(file).SetCreatorType('Pyth', 'TEXT')
+def compile(file, cfile=None, dfile=None):
+ """Byte-compile one Python source file to Python bytecode.
+
+ Arguments:
+
+ file: source filename
+ cfile: target filename; defaults to source with 'c' or 'o' appended
+ ('c' normally, 'o' in optimizing mode, giving .pyc or .pyo)
+ dfile: purported filename; defaults to source (this is the filename
+ that will show up in error messages)
+
+ Note that it isn't necessary to byte-compile Python modules for
+ execution efficiency -- Python itself byte-compiles a module when
+ it is loaded, and if it can, writes out the bytecode to the
+ corresponding .pyc (or .pyo) file.
+
+ However, if a Python installation is shared between users, it is a
+ good idea to byte-compile all modules upon installation, since
+ other users may not be able to write in the source directories,
+ and thus they won't be able to write the .pyc/.pyo file, and then
+ they would be byte-compiling every module each time it is loaded.
+ This can slow down program start-up considerably.
+
+ See compileall.py for a script/module that uses this module to
+ byte-compile all installed files (or all files in selected
+ directories).
+
+ """
+ import os, marshal, __builtin__
+ f = open(file)
+ try:
+ timestamp = os.fstat(file.fileno())
+ except AttributeError:
+ timestamp = long(os.stat(file)[8])
+ codestring = f.read()
+ f.close()
+ if codestring and codestring[-1] != '\n':
+ coestring = codestring + '\n'
+ codeobject = __builtin__.compile(codestring, dfile or file, 'exec')
+ if not cfile:
+ cfile = file + (__debug__ and 'c' or 'o')
+ fc = open(cfile, 'wb')
+ fc.write('\0\0\0\0')
+ wr_long(fc, timestamp)
+ marshal.dump(codeobject, fc)
+ fc.flush()
+ fc.seek(0, 0)
+ fc.write(MAGIC)
+ fc.close()
+ if os.name == 'mac':
+ import macfs
+ macfs.FSSpec(cfile).SetCreatorType('Pyth', 'PYC ')
+ macfs.FSSpec(file).SetCreatorType('Pyth', 'TEXT')