title: python pandas right fill values
body: <p>I am trying to replicate a "right fill" excel-like function which fills the values right till the next value is not null/nan/empty. This "right-fill" exercise is only to be done if the value in the immediate following row in not empty or "nan".
  I have the following pandas dataframe dataset. My current input table is "have". My output table is "want".</p>
  
  <pre><code>import pandas as pd
  have = pd.DataFrame({ \
  "0": pd.Series(["abc","1","something here"]) \
  ,"1": pd.Series(["","2","something here"]) \
  ,"2": pd.Series(["","3","something here"]) \
  ,"3": pd.Series(["something","1","something here"]) \
  ,"4": pd.Series(["","2","something here"]) \
  ,"5": pd.Series(["","","something here"]) \
  ,"6": pd.Series(["","","something here"]) \
  ,"7": pd.Series(["cdf","5","something here"]) \
  ,"8": pd.Series(["","6","something here"]) \
  ,"9": pd.Series(["xyz","1","something here"]) \
  })
  
  want = pd.DataFrame({ \
  "0": pd.Series(["abc","1","something here"]) \
  ,"1": pd.Series(["abc","2","something here"]) \
  ,"2": pd.Series(["abc","3","something here"]) \
  ,"3": pd.Series(["something","1","something here"]) \
  ,"4": pd.Series(["something","2","something here"]) \
  ,"5": pd.Series(["","","something here"]) \
  ,"6": pd.Series(["","","something here"]) \
  ,"7": pd.Series(["cdf","5","something here"]) \
  ,"8": pd.Series(["cdf","6","something here"]) \
  ,"9": pd.Series(["xyz","1","something here"]) \
  })
  </code></pre>