"""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"] # Define an internal helper according to the platform if os.name == "mac": import macfs def set_creator_type(file): macfs.FSSpec(file).SetCreatorType('Pyth', 'PYC ') else: def set_creator_type(file): pass 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): """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). """ f = open(file, 'U') try: timestamp = long(os.fstat(f.fileno()).st_mtime) except AttributeError: timestamp = long(os.stat(file).st_mtime) codestring = f.read() f.close() if codestring and codestring[-1] != '\n': codestring = codestring + '\n' try: codeobject = __builtin__.compile(codestring, dfile or file, 'exec') except SyntaxError, detail: lines = traceback.format_exception_only(SyntaxError, detail) for line in lines: sys.stderr.write(line.replace('File ""', 'File "%s"' % (dfile or file))) return if cfile is None: 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() set_creator_type(cfile) 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 args is None: args = sys.argv[1:] for filename in args: compile(filename) if __name__ == "__main__": main()