title: Sum Values of dicts from dataframes
body: <p>I have a dataframe containing dictionaries in their cells.
  First I filter the columns where there are None values, in order to iterate and explore the ones with dictionaries.
  T iterate over the columns with dictionaries and my goal is to sum the values of those dictionaries and add them to a new column pero column explored.</p>
  
  <p>I keep getting the error:</p>
  
  <blockquote>
    <p>TypeError: 'NoneType' object is not iterable</p>
  </blockquote>
  
  <p>The dataframe columns are something like this:</p>
  
  <pre><code>[In] `df['column_A'].iloc[1]`
  [Out] 
  {'16875259': 0.0,
   '16909775': 9.0,
   '16909808': 214.0,
   '16909816': 3696.0,
   '16910032': 725.0,
   '16910067': 27.0,
   '16910182': 11.0,
   '16910237': 4.0,
   '16910262': 3191.0,
   '16910358': 52.0,
   '16910411': 73.0,
   '16910416': 111.0,
   '16910477': 1869.0,
   '16910598': 2425
  </code></pre>
  
  <h1>The code I managed to build is somthing like this:</h1>
  
  <pre><code>for column in my_df:
      if(my_df[column].values[1]!='None' or my_dfdf1[column].values[1] !=None):
          for column in df1:
              for item in df1[column].values:
                  for i in item:
                      #print(i)
                      # Here I need to sum the values
  </code></pre>
  
  <p>I expect the sum of the values but I keep getting the error:</p>
  
  <blockquote>
    <p>TypeError: 'NoneType' object is not iterable</p>
  </blockquote>