title: Concatenation error (Wrong number of items passed x, placement implies 1)
body: <p>I have a dataframe like so:</p>
  
  <pre><code>a            b
  thing1      1.00
  thing2      2.71 
  </code></pre>
  
  <p>column a is string and column b is float64 and I am trying to convert the frame to where if column b is 1, then return 1 and if the value is above 1 in column b, return 2.71/6,2.71R24,1</p>
  
  <pre><code>a         b       c
  thing1    1       1
  thing2    2.71    2.71/6,2.71R24,1
  </code></pre>
  
  <p>I have tried a function like so </p>
  
  <pre><code>def convert (row):
      if row['b'] == 1.00:
          return '1' 
      else:
          return df['b'].astype(str)+'/6,'+df['b'].astype(str)+'R24,1'
  df['c']  = df.apply(lambda row: convert (row), axis=1)
  </code></pre>
  
  <p>I get the following error:</p>
  
  <pre><code>ValueError: Wrong number of items passed 15, placement implies 1
  </code></pre>
  
  <p>I can't seem to bypass this error?</p>