template.py 文件源码

def __init__(self, autoescape=_DEFAULT_AUTOESCAPE, namespace=None,
                 whitespace=None):
        """Construct a template loader.

        :arg str autoescape: The name of a function in the template
            namespace, such as "xhtml_escape", or ``None`` to disable
            autoescaping by default.
        :arg dict namespace: A dictionary to be added to the default template
            namespace, or ``None``.
        :arg str whitespace: A string specifying default behavior for
            whitespace in templates; see `filter_whitespace` for options.
            Default is "single" for files ending in ".html" and ".js" and
            "all" for other files.

        .. versionchanged:: 4.3
           Added ``whitespace`` parameter.
        """
        self.autoescape = autoescape
        self.namespace = namespace or {}
        self.whitespace = whitespace
        self.templates = {}
        # self.lock protects self.templates.  It's a reentrant lock
        # because templates may load other templates via `include` or
        # `extends`.  Note that thanks to the GIL this code would be safe
        # even without the lock, but could lead to wasted work as multiple
        # threads tried to compile the same template simultaneously.
        self.lock = threading.RLock()