Calculating Cumulative Field Values in ArcMap using a case field

SlobodanKomatina2

I want to calculate cumulative field values using an case field from another column in ArcGIS 10.4. 

For example, if I have an "ID" column and "Count" column inside my attribute table, I want to calculate cumulative values for each year separately. 

I have used this:

How to: Calculate cumulative shape length values of a feature class using the Field Calculator 

I can do that if I select all rows with the same ID and run the field calculator, but that is a lot of manual work, so I want to use "ID" field as case field. 

What is the best way to do that?

DavidPike

count <SPAN class="operator token">=</SPAN> <SPAN class="number token">0</SPAN>
id_list <SPAN class="operator token">=</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="keyword token">def</SPAN> <SPAN class="token function">cummulativeCount</SPAN><SPAN class="punctuation token">(</SPAN>increment<SPAN class="punctuation token">,</SPAN> id_row_value<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
    <SPAN class="keyword token">global</SPAN> count
    <SPAN class="keyword token">global</SPAN> id_list

   
    id_list<SPAN class="punctuation token">.</SPAN>append<SPAN class="punctuation token">(</SPAN>id_row_value<SPAN class="punctuation token">)</SPAN>

    <SPAN class="keyword token">if</SPAN> len<SPAN class="punctuation token">(</SPAN>id_list<SPAN class="punctuation token">)</SPAN><SPAN class="operator token">>=</SPAN><SPAN class="number token">2</SPAN> <SPAN class="operator token">and</SPAN> id_row_value <SPAN class="operator token">==</SPAN> id_list<SPAN class="punctuation token">[</SPAN><SPAN class="operator token">-</SPAN><SPAN class="number token">2</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">:</SPAN> 
        count <SPAN class="operator token">+=</SPAN> int<SPAN class="punctuation token">(</SPAN>increment<SPAN class="punctuation token">)</SPAN>
        

    <SPAN class="keyword token">elif</SPAN> len<SPAN class="punctuation token">(</SPAN>id_list<SPAN class="punctuation token">)</SPAN><SPAN class="operator token"><</SPAN><SPAN class="number token">2</SPAN><SPAN class="punctuation token">:</SPAN>
        count <SPAN class="operator token">+=</SPAN> int<SPAN class="punctuation token">(</SPAN>increment<SPAN class="punctuation token">)</SPAN>
        

    <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
        count <SPAN class="operator token">=</SPAN> int<SPAN class="punctuation token">(</SPAN>increment<SPAN class="punctuation token">)</SPAN>
        

    <SPAN class="keyword token">return</SPAN> count<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

cummulativeCount( !count_! , !id! )