title: Create Python DataFrame from dictionary where keys are the column names and values form the row
body: <p>I am familiar with python but new to panda DataFrames. I have a dictionary like this:</p>
  
  <pre><code>a={'b':100,'c':300}
  </code></pre>
  
  <p>And I would like to convert it to a DataFrame, where b and c are the column names, and the first row is 100,300 (100 is underneath b and 300 is underneath c). I would like a solution that can be generalized to a much longer dictionary, with many more items. Thank you!</p>