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Arcmap Python Label Expression Function "Null"

DevinUnderwood2

I am having difficulty with python parser label function to replace null values with "Unknown Plan" and leave everything else as is. The Unknown Plan is not displaying in the map label.

I have the following:

<SPAN class="keyword token">def</SPAN> FindLabel <SPAN class="punctuation token">(</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN>&nbsp; <SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">is</SPAN>&nbsp; None<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="string token">"Unknown Plan"</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Any idea it is not working ?

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Accepted answers

JoshuaBixby

This will treat NULL and empty strings the same way:

<SPAN class="keyword token">def</SPAN> FindLabel <SPAN class="punctuation token">(</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN>&nbsp; <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">in</SPAN>&nbsp; <SPAN class="punctuation token">(</SPAN>None<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">""</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="string token">"Unknown Plan"</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN>‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

All comments

ScottFraser3

This was helpful and allowed me to find the solution. For the sake of clarity, for those to come in the future...

Problem: The label expression included fields for "Building numbers" and "Unit numbers." However, labels only appear where there were actual data entries in those fields. Regular addresses [single family home at 123 Main St.] had no labels displayed because there wasn't date entered for either a "building number" nor a "unit number". Those empty fields were "<Null>".

Solution:

Select all records where "building number" and/or "unit number" were "<Null>.
Calculate these fields to fill with blank strings [" "]
Voilà!

Now labels appear:

For all locations, regardless if there are building or unit numbers in those related fields.
Locations with building and/or unit info, also have this data appearing in the labels.

DevinUnderwood2

Interesting, I went ahead and changed it to the following.

"999" is the coded value for "unknown"

My retired line labels are still showing.

<SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">[</SPAN>DIAMETER<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">==</SPAN> <SPAN class="string token">"999"</SPAN> <SPAN class="operator token">and</SPAN> shapeDict<SPAN class="punctuation token">[</SPAN>oid<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">></SPAN> <SPAN class="number token">50</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="string token">"Size ?"</SPAN> <SPAN class="operator token">+</SPAN>&nbsp; <SPAN class="string token">'\x22'</SPAN> <SPAN class="operator token">+</SPAN> <SPAN class="string token">" "</SPAN> <SPAN class="operator token">+</SPAN> <SPAN class="punctuation token">[</SPAN>MATERIAL<SPAN class="punctuation token">]</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

DanPatterson_Retired

line 11 ... in ["999"] should be a list or change it to an equality check

DevinUnderwood2

I am successful in the flowing label expression to not show retired pipe lines.

lyrName <SPAN class="operator token">=</SPAN> <SPAN class="string token">" Main Lines Plan Label"</SPAN>
shapeDict <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</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>lyrName<SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="string token">"OID@"</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">"SHAPE@LENGTH"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">as</SPAN> cursor<SPAN class="punctuation token">:</SPAN>
&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; shapeDict<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> <SPAN class="operator token">=</SPAN> row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="keyword token">def</SPAN> <SPAN class="token function">FindLabel</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>OBJECTID<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>AGENCY<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>GIS_STATUS<SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp; oid <SPAN class="operator token">=</SPAN> int<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>OBJECTID<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">[</SPAN>AGENCY<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">==</SPAN> <SPAN class="string token">"ABANDON"</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> None
&nbsp;&nbsp; <SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">[</SPAN>GIS_STATUS<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">==</SPAN> <SPAN class="string token">"Retired"</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> None 
&nbsp;&nbsp; <SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">in</SPAN>&nbsp; <SPAN class="punctuation token">(</SPAN>None<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">" "</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">and</SPAN> shapeDict<SPAN class="punctuation token">[</SPAN>oid<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">></SPAN> <SPAN class="number token">50</SPAN> <SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="string token">"Plan ?"</SPAN>
&nbsp;&nbsp; <SPAN class="keyword token">elif</SPAN> shapeDict<SPAN class="punctuation token">[</SPAN>oid<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">></SPAN> <SPAN class="number token">50</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<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>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

However, I am having trouble with not displaying labels for pipelines that have been attributed as retired for another layer. Any ideas why?

lyrName <SPAN class="operator token">=</SPAN> <SPAN class="string token">"Main Lines Diameter &&nbsp; Material Label"</SPAN>
shapeDict <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</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>lyrName<SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="string token">"OID@"</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">"SHAPE@LENGTH"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">as</SPAN> cursor<SPAN class="punctuation token">:</SPAN>
&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; shapeDict<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> <SPAN class="operator token">=</SPAN> row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN>
<SPAN class="keyword token">def</SPAN> FindLabel <SPAN class="punctuation token">(</SPAN> <SPAN class="punctuation token">[</SPAN>OBJECTID<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>DIAMETER<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>MATERIAL<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>AGENCY<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>GIS_STATUS<SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; oid <SPAN class="operator token">=</SPAN> int<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>OBJECTID<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; 
 
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">[</SPAN>GIS_STATUS<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">==</SPAN> <SPAN class="string token">"Retired"</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> None
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">[</SPAN>DIAMETER<SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">in</SPAN> <SPAN class="string token">"999"</SPAN> <SPAN class="operator token">and</SPAN> shapeDict<SPAN class="punctuation token">[</SPAN>oid<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">></SPAN> <SPAN class="number token">50</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="string token">"Size ?"</SPAN> <SPAN class="operator token">+</SPAN>&nbsp; <SPAN class="string token">'\x22'</SPAN> <SPAN class="operator token">+</SPAN> <SPAN class="string token">" "</SPAN> <SPAN class="operator token">+</SPAN> <SPAN class="punctuation token">[</SPAN>MATERIAL<SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">[</SPAN>DIAMETER<SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">in</SPAN>&nbsp; <SPAN class="punctuation token">(</SPAN>None<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">" "</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">and</SPAN> shapeDict<SPAN class="punctuation token">[</SPAN>oid<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">></SPAN> <SPAN class="number token">50</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="string token">"Size ?"</SPAN> <SPAN class="operator token">+</SPAN>&nbsp; <SPAN class="string token">'\x22'</SPAN> <SPAN class="operator token">+</SPAN> <SPAN class="string token">" "</SPAN> <SPAN class="operator token">+</SPAN> <SPAN class="punctuation token">[</SPAN>MATERIAL<SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN>DIAMETER<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">+</SPAN> <SPAN class="string token">'\x22'</SPAN> <SPAN class="operator token">+</SPAN> <SPAN class="string token">" "</SPAN> <SPAN class="operator token">+</SPAN> <SPAN class="punctuation token">[</SPAN>MATERIAL<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>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

curtvprice

Another downside of calculating labels on the fly is the huge performance hit you can get if your labeling logic is complex. A middle way would be to copy your table locally (or to in_memory), calculate text labels using a cursor, join your features to the table and label using the text field. I know it sounds difficult but if you really don't want to edit your data that may be a valid approach.

DevinUnderwood2

I am testing it out by taking your suggestion of adding a new length field and using the following expression.

It is not working as I think I have to specify when it is a non text field. Is that correct ?

<SPAN class="keyword token">def</SPAN> FindLabel <SPAN class="punctuation token">(</SPAN> <SPAN class="punctuation token">[</SPAN>LENGTH<SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN>&nbsp; <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> Double <SPAN class="punctuation token">(</SPAN> <SPAN class="punctuation token">[</SPAN>LENGTH<SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">)</SPAN>&nbsp;&nbsp; <SPAN class="operator token">></SPAN> <SPAN class="number token">50</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

TedKowal

Sometimes a little editing can go a long ways in saving time and headaches.... unless you want to run the cursor script the only other automatize way I can think of is to write a python script that activates on mxd open event which would populate/referesh the "myLength" column for you -- but that would involve writing an add-in.

DevinUnderwood2

Thanks, I will look into this.

At a first look I don't see how all this can be included in a label expression. my goal is not needing to edit the actual data at all.

TedKowal

You cannot simply pass the geometry into a label string (At least I have never figured out how) so you would have to do something like this:

<SPAN class="keyword token">import</SPAN> arcpy
lyrName <SPAN class="operator token">=</SPAN> <SPAN class="string token">"AADT_2015"</SPAN>
shapeDict <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</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>lyrName<SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="string token">"OID@"</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">"SHAPE@LENGTH"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">as</SPAN> cursor<SPAN class="punctuation token">:</SPAN>
&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; shapeDict<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> <SPAN class="operator token">=</SPAN> row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN>

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">FindLabel</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>OBJECTID<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp; oid <SPAN class="operator token">=</SPAN> int<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>OBJECTID<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> shapeDict<SPAN class="punctuation token">[</SPAN>oid<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">></SPAN> <SPAN class="number token">50</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="string token">"BIG"</SPAN>
&nbsp;&nbsp; <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="string token">"Small"</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>‍</SPAN></SPAN>

Personally I feel that is over kill..... If I were doing it I would create a new field say myLength as a double... use the field calculator to calculate the segment length (!shape.length! I believe )...then pass [myLength] to your label function as you wrote it above using [myLength] instead of [SHAPE.LEN]

DevinUnderwood2

Great feedback, thanks.

With your help I was able to use the following python label expression in my mapbook.

For any water pipeline attributed with, "abandon", do not label. Also, if any pipeline is null then label as seen below.

<SPAN class="keyword token">def</SPAN> FindLabel <SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>AGENCY<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">[</SPAN>AGENCY<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">==</SPAN> <SPAN class="string token">"ABANDON"</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> None
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">in</SPAN>&nbsp; <SPAN class="punctuation token">(</SPAN>None<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">" "</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="string token">"Plan ?"</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<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>

I need to also only show pipeline labels for pipe greater than 50 feet. I tested out the following and it doesn't work. I would then need to add it to my current expression.

Any ideas what is wrong with my expression.

Thanks

<SPAN class="keyword token">def</SPAN> FindLabel <SPAN class="punctuation token">(</SPAN> <SPAN class="punctuation token">[</SPAN>SHAPE<SPAN class="punctuation token">.</SPAN>LEN<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN>&nbsp; <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">[</SPAN>SHAPE<SPAN class="punctuation token">.</SPAN>LEN<SPAN class="punctuation token">]</SPAN>&nbsp; <SPAN class="operator token">></SPAN> <SPAN class="number token">50</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN> ‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

DanPatterson_Retired

As you said ... 'old vba scripting' ....

In python there is only one None, everything is an empty version of a type...

a refresher... /blogs/dan_patterson/2016/11/03/before-i-forget-18-those-pesky-null-things

and a clear statement

<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> type<SPAN class="punctuation token">(</SPAN><SPAN class="string token">""</SPAN><SPAN class="punctuation token">)</SPAN>
<SPAN class="operator token"><</SPAN><SPAN class="keyword token">class</SPAN> <SPAN class="string token">'str'</SPAN><SPAN class="operator token">></SPAN>
<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> type<SPAN class="punctuation token">(</SPAN>None<SPAN class="punctuation token">)</SPAN>
<SPAN class="operator token"><</SPAN><SPAN class="keyword token">class</SPAN> <SPAN class="string token">'NoneType'</SPAN><SPAN class="operator token">></SPAN>‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

TedKowal

For me the empty cells would be null, lot's depends on how the database/tables have been defined...

Using the old VBA scripting language this was never an issue...but with python (I have to check for everything!) Not to mention unprintable control characters.... but this is off subject...... I am a very reluctant python users.... vb rest in peace!

DevinUnderwood2

I agree that in general, nulls, empty, NA and spaces always present issues which I don't remember how to address right away.

Technically, my empty fields do not have spaces since I never typed anything in, I would assume?

So, you bring up a good point, what exactly are the empty fields represented by ?

TedKowal

What happens when there are multiple spaces......

Would not [PLAN].strip() in (None, "") work better and a little more bullet proof?

------ I still say Python has issues with nulls, empty, NA and spaces ....

DevinUnderwood2

<SPAN class="keyword token">def</SPAN> FindLabel <SPAN class="punctuation token">(</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN>&nbsp; <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">in</SPAN>&nbsp; <SPAN class="punctuation token">(</SPAN>None<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">" "</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="string token">"Unknown Plan"</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN>PLAN<SPAN class="punctuation token">]</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

This work perfect, thank you. Good to know that an empty string treated the same for label expressions and the field calculator. Null is not though, having to use None to represent Null in label expressions.

DevinUnderwood2

Good point, I have empty strings, how would I represent empty strings, not Null ?

JoshuaBixby

Nulls show up as <Null>, I think you have empty strings.

DevinUnderwood2

I made Dan's suggested changes and still no luck.

I should of elaborated what string PLAN field is. The blank fields are Null.

JoshuaBixby

Not to ask the obvious, but is the [PLAN] field an empty string instead of NULL?

DanPatterson_Retired

line 2 the ( ) brackets aren't needed

line 3 is indented improperly

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