CSV 値のマスク

CSVファイルのヘッダー行があり、nameを含んでいる場合、
nameをハッシュ する。

import csv

"""おなじみ動的クラス"""
def Dynamic(name, fields):
    """ returns a class object which has fields attribute.
    the class is iterable."""
    dic = dict([x,None] for x in fields)
    o = type(name, (_dynamic,), dic)
    o._fields = fields
    return o
class _dynamic(object):
    _fields = []

    def __init__(self, *args, **kwargs):
        for i,value in enumerate(args[0]):
            setattr(self, self._fields[i], value)

    def __iter__(self):
        for field in self._fields:
            yield getattr(self, field)

    def __str__(self):
        if len(self._fields) == 0:
            return "[]"
        l = "["
        for field in self._fields:
            l += getattr(self, field).__str__() + ", "
        return l[0:-2] + "]"
   
    def __setattr__(self, name, value):
        if name == "_fields":
            for field in set(self._fields) - set(value):
                delattr(self, field)
            for field in set(value) - set(self._fields):
                super(_dynamic, self).__setattr__(field, None)
        super(_dynamic, self).__setattr__(name, value)
           
if __name__ == "__main__":
    reader = csv.reader(file(inputfilename))
    writer = csv.writer(file(outputfilename, "w"))
    Personal = Dynamic("Personal", reader.next())
    for line in reader:
        person = Personal(line)
        person.name=hash(person.name)
        writer.writerow(list(person))

動的に属性を変更可能なクラス (その2)

前回の内容では field を変更したときに値がすべて削除された。
できれば field が a, b, cから b, c, dに変更されたときにはb, c の値を保存しておきたいのでプログラムを修正。

def Dynamic(name, fields):
    """ returns a class object which has fields attribute.
    the class is iterable."""
    dic = dict([x,None] for x in fields)
    o = type(name, (_dynamic,), dic)
    o._fields = fields
    return o
class _dynamic(object):
    _fields = []

    def __init__(self, *args, **kwargs):
        for i,value in enumerate(args[0]):
            setattr(self, self._fields[i], value)

    def __iter__(self):
        for field in self._fields:
            yield getattr(self, field)

    def __setattr__(self, name, value):
        if name == "_fields":
            for field in set(self._fields) - set(value):
                delattr(self, field)
            for field in set(value) - set(self._fields):
                super(_dynamic, self).__setattr__(field, None)
        super(_dynamic, self).__setattr__(name, value)

動的に属性を変更可能なクラス

namedtupleはとても便利だが、値の変更ができない。
値の変更可能な、エセnamedtuple を作ってみました。
namedtuple にはあってこれにはない属性がいろいろあるけど、そこは追々作るということで。

def Dynamic(name, fields):
    """ returns a class object which has fields attribute.
    the class is iterable."""
    dic = dict([x,None] for x in fields)
    o = type(name, (_dynamic,), dic)
    o._fields = fields
    return o
class _dynamic(object):
    _fields = []

    def __init__(self, *args, **kwargs):
        for i,value in enumerate(args[0]):
            setattr(self, self._fields[i], value)

    def __iter__(self):
        for field in self._fields:
            yield getattr(self, field)

    def __setattr__(self, name, value):
        if name == "_fields":
            for field in self._fields:
                delattr(self, field)
            for field in value:
                super(_dynamic, self).__setattr__(field, None)
        super(_dynamic, self).__setattr__(name, value)