I've been tasked with updating attribute table fields with file paths to image files in a folder based on a unique ID. I'm having trouble thinking up a script that will do this? I'm working on a standalone script in ArcGIS Pro 2.3.1 Arcpy.
This is an example of how the table should look. Every JPG has a unique ID that matches the Post_Number field unique ID. Currently, the paths to the JPGs are entered manually into the table, and there are 1000s of them.

All I've done so far is create a cursor that searches the Post_Number and Photo fields.
<SPAN class="keyword token">import</SPAN> arcpy<SPAN class="punctuation token">,</SPAN> os
fc <SPAN class="operator token">=</SPAN> r<SPAN class="string token">'pathto\Projects\DOT_SignInventory\Data.gdb\WCDOT_Signs'</SPAN>
fields <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'Post_Number'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Photo'</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="keyword token">with</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>SearchCursor<SPAN class="punctuation token">(</SPAN>fc<SPAN class="punctuation token">,</SPAN> fields<SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">as</SPAN> cursor<SPAN class="punctuation token">:</SPAN>
<SPAN class="keyword token">for</SPAN> row <SPAN class="keyword token">in</SPAN> cursor<SPAN class="punctuation token">:</SPAN>
<SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN>u<SPAN class="string token">"{0}, {1}"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN><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="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>