title: add input to existing dictionary entry without overwriting
body: <p>im trying to add to a dictionary that looks like the following </p>
  
  <pre><code>d = {"feline" : {"lion" : 22,
  "tiger" : 88 },
  "canine" : {"dog" : 12,
  "wolf" : 53,
  "coyote" : 77} }
  </code></pre>
  
  <p>im trying to add 'cat' and 55 to the dictionary under feline but im not sure how to acess this. this is what i attempted</p>
  
  <pre><code>fp = raw_input("enter a feline type")
  apa = input("enter an amount")
  for keys in d :
      if fp not in d[keys] :
          d['feline'] = {fp : int(apa)}
  </code></pre>
  
  <p>but when i do this the values such as tiger and lion get deleted and the input is replaced for them. for example if i want to add cat under the 'feline' section, usin the above code i get...</p>
  
  <pre><code>{'feline': {'cat ': 55}, 'canine': {'coyote': 77, 'wolf': 53, 'dog': 12}}
  </code></pre>
  
  <p>how do i keep lion and tiger in the dictionary without overwriting them using dictionaries</p>