Object#try in python

perhaps.py

# -*- coding: utf-8 -*-
from __future__ import (print_function, division, absolute_import, unicode_literals, )

from operator import methodcaller


class Perhaps(object):
    '''
    >>> p = Perhaps('hoge huga foo')
    >>> P = p.try_('replace', 'huga', 'muoo').try_('upper').apply(print)
    HOGE MUOO FOO
    >>> p = Perhaps(None)
    >>> p.try_('replace', 'huga', 'muoo').try_('upper').var is None
    True
    '''

    def __init__(self, var):
        self.var = var

    def try_(self, methodname, *args, **kw):
        v = self.var
        if v is None:
            return self
        else:
            self.var = methodcaller(methodname, *args, **kw)(v)
            return self

    def apply(self, func, *args, **kw):
        v = self.var
        if v is None:
            return self
        else:
            self.var = func(self.var, *args, **kw)
            return self


if __name__ == '__main__':
    import doctest
    doctest.testmod()