How to Calculate or use Update Cursor to concatenate fields only for values that are None

enterprisemaps-gwest

I have two values, one date and one time, I would like to only calculate my new field if the value for the field is NULL.  How do I do so using ArcPy?  My current code reads as.

calcExpression <SPAN class="operator token">=</SPAN> <SPAN class="string token">"!ORIGDTDATE!+\" \"+ !ORIGDTTIME!"</SPAN>
 arcpy<SPAN class="punctuation token">.</SPAN>CalculateField_management<SPAN class="punctuation token">(</SPAN>self<SPAN class="punctuation token">.</SPAN>line_ticket_feature_class<SPAN class="punctuation token">,</SPAN><SPAN class="string token">"emergency_overdue"</SPAN><SPAN class="punctuation token">,</SPAN>calcExpression<SPAN class="punctuation token">,</SPAN><SPAN class="string token">"PYTHON_9.3"</SPAN><SPAN class="punctuation token">)</SPAN>
 arcpy<SPAN class="punctuation token">.</SPAN>CalculateField_management<SPAN class="punctuation token">(</SPAN>self<SPAN class="punctuation token">.</SPAN>poly_ticket_feature_class<SPAN class="punctuation token">,</SPAN><SPAN class="string token">"emergency_overdue"</SPAN><SPAN class="punctuation token">,</SPAN>calcExpression<SPAN class="punctuation token">,</SPAN><SPAN class="string token">"PYTHON_9.3"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

MitchHolley1

Something like this should work.

<SPAN class="keyword token">import</SPAN> arcpy

date <SPAN class="operator token">=</SPAN> <SPAN class="string token">'date_field'</SPAN>
time <SPAN class="operator token">=</SPAN> <SPAN class="string token">'time_field'</SPAN>
new <SPAN class="operator token">=</SPAN> <SPAN class="string token">'new_field'</SPAN>
feature <SPAN class="operator token">=</SPAN> r<SPAN class="string token">'path to dataset'</SPAN>

<SPAN class="keyword token">with</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>UpdateCursor<SPAN class="punctuation token">(</SPAN>feature<SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>new<SPAN class="punctuation token">,</SPAN> date<SPAN class="punctuation token">,</SPAN> time<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">as</SPAN> cursor<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">for</SPAN> row <SPAN class="keyword token">in</SPAN> cursor<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">is</SPAN> None<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> str<SPAN class="punctuation token">(</SPAN>row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">+</SPAN> <SPAN class="string token">'/'</SPAN> <SPAN class="operator token">+</SPAN> str<SPAN class="punctuation token">(</SPAN>row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">2</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># can separate the fields with anything you'd like</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; cursor<SPAN class="punctuation token">.</SPAN>updateRow<SPAN class="punctuation token">(</SPAN>row<SPAN class="punctuation token">)</SPAN>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<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>