find.py 文件源码

def parse_python_source(fn):
    """Parse the file 'fn' and return two things:

    1. The AST tree.
    2. A list of lines of the source line (typically used for verbose error
       messages).

    If the file has a syntax error in it, the first argument will be None.
    """
    # Read the file's contents to return it.
    # Note: we make sure to use universal newlines.
    try:
        contents = open(fn, 'rU').read()
        lines = contents.splitlines()
    except (IOError, OSError), e:
        logging.error("Could not read file '%s'." % fn)
        return None, None

    # Convert the file to an AST.
    try:
        ast = compiler.parse(contents)
    except SyntaxError, e:
        err = '%s:%s: %s' % (fn, e.lineno or '--', e.msg)
        logging.error("Error processing file '%s':\n%s" %
                      (fn, err))
        return None, lines
    except TypeError, e:
        # Note: this branch untested, applied from a user-submitted patch.
        err = '%s: %s' % (fn, str(e))
        logging.error("Error processing file '%s':\n%s" %
                      (fn, err))
        return None, lines

    return ast, lines