我想将INI文件映射为python对象。所以如果文件有:
[UserOptions]
SampleFile = sample.txt
SamplePort = 80
SampleInt = 1
Sample = Aja
SampleDate = 10/02/2008
然后我想:
c = Configuration('sample.ini')
c.UserOptions.SamplePort = 90
我正在寻找 setattr ,但我收到了一个递归错误。
这就是我所拥有的:
class Configuration:
def __init__ (self, fileName):
cp = SafeConfigParser()
cp.read(fileName)
self.__parser = cp
self.fileName = fileName
def __getattr__ (self, name):
if name in self.__parser.sections():
return Section(name, self.__parser)
else:
return None
def __str__ (self):
p = self.__parser
result = []
result.append('<Configuration from %s>' % self.fileName)
for s in p.sections():
result.append('[%s]' % s)
for o in p.options(s):
result.append('%s=%s' % (o, p.get(s, o)))
return '\n'.join(result)
class Section:
def __init__ (self, name, parser):
self.__name = name
self.__parser = parser
def __getattr__ (self, name):
if self.__dict__.has_key(name): # any normal attributes are handled normally
return __getattr__(self, item)
else:
return self.__parser.get(self.name, name)
def __setattr__(self, item, value):
"""Maps attributes to values.
Only if we are initialised
"""
if self.__dict__.has_key(item): # any normal attributes are handled normally
dict.__setattr__(self, item, value)
else:
self.__parser.set('UserOptions',item, value)
现在我想知道为什么在self.__parser.set('UserOptions',item, value)
我得到了错误。我读了蟒蛇文档,我不知道该怎么做。我怀疑我需要存储一个带有字段名称的字典,然后先看一下但是怎么样?
答案 0 :(得分:4)
您正在尝试按要求获取这些部分。但是迭代部分和选项并在__init__
中将它们添加为属性要容易得多。我编辑了我的例子来支持setattr。您的问题已解释为here您要在__setattr__
中分配属性,而应使用__dict__
代替
from ConfigParser import SafeConfigParser
class Section:
def __init__(self, name, parser):
self.__dict__['name'] = name
self.__dict__['parser'] = parser
def __setattr__(self, attr, value):
self.__dict__[attr] = str(value)
self.parser.set(self.name, attr, str(value))
class Configuration(object):
def __init__(self, fileName):
self.__parser = SafeConfigParser()
self.__parser.read(fileName)
self.fileName = fileName
for section in self.__parser.sections():
setattr(self, section, Section(section, self.__parser))
for option in self.__parser.options(section):
setattr(getattr(self, section), option,
self.__parser.get(section, option))
def __getattr__(self, attr):
self.__parser.add_section(attr)
setattr(self, attr, Section(attr, self.__parser))
return getattr(self, attr)
def save(self):
f = open(self.fileName, 'w')
self.__parser.write(f)
f.close()
c = Configuration('config.ini')
print dir(c) -> will print all sections
print dir(c.UserOptions) -> will print all user options
print c.UserOptions.sampledate
c.new.value = 10
c.save()
答案 1 :(得分:4)
您的问题出在Section.__init__
。当您设置self.__name = name
时,它会调用您的__setattr__
方法,但在__dict__
中找不到密钥,因此会转到
self.__parser.set('UserOptions',item, value)
所以现在它需要self.__parser
。
尚未设定。所以它试图使用__getattr__
来获取它。它发送它寻找self.__parser
。还没有设定。所以它试图使用__getattr__
来获取它。所以......你明白了: - )
避免这种情况的一种方法是在Section.__setattr__
中添加条件
if item.startswith('_') or self.__dict__.has_key(item):
^^^^^^^^^^^^^^^^^^^^^^^
...
这将确保在初始化时正确设置__name
和__parser
。