"""Routine to "compile" a .py file to a .pyc (or .pyo) file.

This module has intimate knowledge of the format of .pyc files.

"""

import __builtin__

import imp

import marshal

import os

import sys

import traceback

MAGIC = imp.get_magic()

__all__ = ["compile", "main", "PyCompileError"]

class PyCompileError(Exception):

"""Exception raised when an error occurs while attempting to

compile the file.

To raise this exception, use

raise PyCompileError(exc_type,exc_value,file[,msg])

where

exc_type: exception type to be used in error message

type name can be accesses as class variable

'exc_type_name'

exc_value: exception value to be used in error message

can be accesses as class variable 'exc_value'

file: name of file being compiled to be used in error message

can be accesses as class variable 'file'

msg: string message to be written as error message

If no value is given, a default exception message will be given,

consistent with 'standard' py_compile output.

message (or default) can be accesses as class variable 'msg'

"""

def __init__(self, exc_type, exc_value, file, msg=''):

exc_type_name = exc_type.__name__

if exc_type is SyntaxError:

tbtext = ''.join(traceback.format_exception_only(exc_type, exc_value))

errmsg = tbtext.replace('File "<string>"', 'File "%s"' % file)

else:

errmsg = "Sorry: %s: %s" % (exc_type_name,exc_value)

Exception.__init__(self,msg or errmsg,exc_type_name,exc_value,file)

self.exc_type_name = exc_type_name

self.exc_value = exc_value

self.file = file

self.msg = msg or errmsg

def __str__(self):

return self.msg

def wr_long(f, x):

"""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, dfile=None, doraise=False):

"""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)

doraise: flag indicating whether or not an exception should be

raised when a compile error is found. If an exception

occurs and this flag is set to False, a string

indicating the nature of the exception will be printed,

and the function will return to the caller. If an

exception occurs and this flag is set to True, a

PyCompileError exception will be raised.

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).

"""

with open(file, 'U') as f:

try:

timestamp = long(os.fstat(f.fileno()).st_mtime)

except AttributeError:

timestamp = long(os.stat(file).st_mtime)

codestring = f.read()

try:

codeobject = __builtin__.compile(codestring, dfile or file,'exec')

except Exception,err:

py_exc = PyCompileError(err.__class__, err, dfile or file)

if doraise:

raise py_exc

else:

sys.stderr.write(py_exc.msg + '\n')

return

if cfile is None:

cfile = file + (__debug__ and 'c' or 'o')

with open(cfile, 'wb') as fc:

fc.write('\0\0\0\0')

wr_long(fc, timestamp)

marshal.dump(codeobject, fc)

fc.flush()

fc.seek(0, 0)

fc.write(MAGIC)

def main(args=None):

"""Compile several source files.

The files named in 'args' (or on the command line, if 'args' is

not specified) are compiled and the resulting bytecode is cached

in the normal manner. This function does not search a directory

structure to locate source files; it only compiles files named

explicitly. If '-' is the only parameter in args, the list of

files is taken from standard input.

"""

if args is None:

args = sys.argv[1:]

rv = 0

if args == ['-']:

while True:

filename = sys.stdin.readline()

if not filename:

break

filename = filename.rstrip('\n')

try:

compile(filename, doraise=True)

except PyCompileError as error:

rv = 1

sys.stderr.write("%s\n" % error.msg)

except IOError as error:

rv = 1

sys.stderr.write("%s\n" % error)

else:

for filename in args:

try:

compile(filename, doraise=True)

except PyCompileError as error:

# return value to indicate at least one failure

rv = 1

sys.stderr.write("%s\n" % error.msg)

return rv

if __name__ == "__main__":

sys.exit(main())