templates.py 文件源码

def extract_jinja_error(exc_info, fnames_prefix=None):
    '''
    Extract relevant informations from a Jinja2 exception.

    *exc_info* should be a ``(exc_type, exc_value, traceback)`` tuple, as
    returned by :func:`sys.exc_info`.

    Return a ``(stack, error)`` tuple, where *stack* a list of lines describing
    the stack that led to the error, and *error* the description of the error.

    Raise a :class:`TypeError` if the error is not a supported Jinja2 error.
    '''
    exc_type, exc_value, tb = exc_info
    if exc_type is jinja2.UndefinedError:
        prefix = u'Undefined variable'
    elif exc_type is jinja2.TemplateSyntaxError:
        prefix = u'Syntax error'
    else:
        raise TypeError(exc_type)

    stack_lines = []
    jinja_tb = [x for x in traceback.extract_tb(tb)
                if x[2] in ('top-level template code', 'template')]
    for file_name, line, func_name, text in jinja_tb:
        if fnames_prefix is not None:
            file_name = file_name[len(fnames_prefix) + 1:]
        stack_lines.append(u'  File "%s", line %s' % (file_name, line))
        stack_lines.append(u'    %s' % text)

    error_details = unicode(exc_value)
    error_details = error_details.rstrip('.')
    return stack_lines, u'%s: %s' % (prefix, error_details)