title: String manipulation in Python (All upper and lower case derivatives of a word)
body: <p>I have to read in a word, and create an array which stores every variation of upper and lower case characters for this word in an array. For example with the word "abc". I need to find a way to retrieve every upper and lower case version of "abc" (abc, Abc, ABc, ABC, AbC, abC, and aBC). The string may also include numbers which should be left alone.</p>
  
  <p>I know I would have to use recursion here in order to get every variation, but I'm just not quite sure how, or if there are any python libraries that provide this kind of operation.</p>
  
  <p>Any help or tips is greatly appreciated!</p>