python - 我如何动态引用Python中的变量

Question

看我的简单类:

import sys

class Foo(object):

  def __init__(self):
    self.frontend_attrs = ['name','ip_address','mode','port','max_conn']
    self.backend_attrs  = ['name','balance_method','balance_mode']

上面的 init 方法创建了两个列表，我想动态地引用它们:

def sanity_check_data(self):
  self.check_section('frontend')
  self.check_section('backend')

def check_section(self, section):
  # HERE IS THE DYNAMIC REFERENCE
  for attr in ("self.%s_attrs" % section):
    print attr

但是当我这样做时，python 会提示对 ("self.%s_attrs"% section) 的调用。

我读到有人使用 get_attr 动态查找模块...

getattr(sys.modules[__name__], "%s_attrs" % section)()

这可以用于字典吗？

Answer 1

我想你要找的是getattr() .像这样:

def check_section(self, section):
    for attr in getattr(self, '%s_attrs' % section):
        print attr

尽管在这种情况下，为了简单起见，您最好使用字典:

class Foo(object):

  def __init__(self):
    self.my_attrs = {
      'frontend': ['name','ip_address','mode','port','max_conn'],
      'backend': ['name','balance_method','balance_mode'],
    }

  def sanity_check_data(self):
    self.check_section('frontend')
    self.check_section('backend')

  def check_section(self, section):
    # maybe use self.my_attrs.get(section) and add some error handling?
    my_attrs = self.my_attrs[section]
    for attr in my_attrs:
      print attr