【backtrader源码解析30】flt.py和fillers.py源码解析(枯燥，仅供参考)

flt.py代码里面主要写了一个简单的Filter类

from __future__ import (absolute_import, division, print_function,
                        unicode_literals)


from .metabase import MetaParams
from .utils.py3 import with_metaclass


__all__ = ['Filter']

# Filte