In [ ]:

    




    

In [1]:

    

class StrKeyDict0(dict):
    
    def __missing__(self, key):
        if isinstance(key, str):
            raise KeyError(key)
            
        return self[str(key)]
    
    def get(self, key, default=None):
        try:
            return self[key]
        except KeyError:
            return default
        
    def __contains__(self, key):
        return key in self.keys() or str(key) in self.keys()


    

In [3]:

    

d = StrKeyDict0([('2', 'two'), ('4', 'four')])


    

In [4]:

    

d['2']


    

    
Out[4]:





'two'

In [5]:

    

d[4]


    

    
Out[5]:





'four'

In [6]:

    

d[1]


    

    




---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-6-abe283337115> in <module>()
----> 1 d[1]

<ipython-input-1-e6e4506521a3> in __missing__(self, key)
      5             raise KeyError(key)
      6 
----> 7         return self[str(key)]
      8 
      9     def get(self, key, default=None):

<ipython-input-1-e6e4506521a3> in __missing__(self, key)
      3     def __missing__(self, key):
      4         if isinstance(key, str):
----> 5             raise KeyError(key)
      6 
      7         return self[str(key)]

KeyError: '1'

In [7]:

    

d['1']


    

    




---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-7-e142bffca921> in <module>()
----> 1 d['1']

<ipython-input-1-e6e4506521a3> in __missing__(self, key)
      3     def __missing__(self, key):
      4         if isinstance(key, str):
----> 5             raise KeyError(key)
      6 
      7         return self[str(key)]

KeyError: '1'

In [8]:

    

d.get(2)


    

    
Out[8]:





'two'

In [9]:

    

d.get('2')


    

    
Out[9]:





'two'

In [10]:

    

d.get(1,'N/A')


    

    
Out[10]:





'N/A'

In [12]:

    

d.get('1', 'N/A')


    

    
Out[12]:





'N/A'

In [13]:

    

2 in d


    

    
Out[13]:





True

In [14]:

    

'2' in d


    

    
Out[14]:





True

In [15]:

    

import collections


    

In [16]:

    

class StrKeyDict(collections.UserDict):
    
    def __missing__(self, key):
        if isinstance(key, str):
            raise KeyError(key)
            
        return self[str(key)]

    def __contains__(self, key):
        return str(key) in self.data
    
    def __setitem__(self, key, item):
        self.data[str(key)] = item


    

In [18]:

    

d = StrKeyDict([(2, 'two'), ('4', 'four')])


    

In [19]:

    

sorted(d.keys())


    

    
Out[19]:





['2', '4']

In [20]:

    

d[2], d['2']


    

    
Out[20]:





('two', 'two')

In [21]:

    

d[4], d['4']


    

    
Out[21]:





('four', 'four')

In [22]:

    

d['1']


    

    




---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-22-e142bffca921> in <module>()
----> 1 d['1']

/anaconda3/lib/python3.6/collections/__init__.py in __getitem__(self, key)
    988             return self.data[key]
    989         if hasattr(self.__class__, "__missing__"):
--> 990             return self.__class__.__missing__(self, key)
    991         raise KeyError(key)
    992     def __setitem__(self, key, item): self.data[key] = item

<ipython-input-16-042d138b893e> in __missing__(self, key)
      3     def __missing__(self, key):
      4         if isinstance(key, str):
----> 5             raise KeyError(key)
      6 
      7         return self[str(key)]

KeyError: '1'

In [23]:

    

d.get('2'), d.get('4')


    

    
Out[23]:





('two', 'four')

In [25]:

    

d.get(1, 'N/A'), d.get('1', 'N/A')


    

    
Out[25]:





('N/A', 'N/A')

In [ ]: