Hello! I recently posted a question about python dictionaries and here I am again struggling with them.. I am now trying to use them to change feature class names. Problem: I have a list of 77 feature classes and I need to change their names from codes to names using a python dictionary. For example: Feature class name: T14_single_points New name that I need: Alachua I am not getting any errors when running this code but I am not getting any results either. import arcpy # script to change fc name using a dictionary arcpy . env . workspace = r "D:\APRX_MXDS\USA_Parcels_2019_Project\test.gdb" arcpy . env . overwriteOutput = True fc_list = arcpy . ListFeatureClasses ( "points*" ) # list of fc that end with points # dictionary county_codes = { 14 : "Bradford" , 15 : "Brevard" , 16 : "Broward" } for fc in fc_list : # loop through the feature classes key = "{[1:3]}" . format ( fc . name ) # let the second and third characters in the fc name be the key if key in county_codes : fc = county_codes . get ( key ) # assign the value in the dictionary as the new feature class name thank you!

I thought that was what you might be thinking. Take a step back and study your code for a minute, and ask yourself, what exactly is fc? It's just a variable and the value of that variable changes as the for loop progresses. Run the snippet of code: for fc in fc_list : key = "{[1:3]}" . format ( fc . name ) if key in county_codes : print ( fc ) fc = county_codes . get ( key ) print ( fc ) And when it's done, take a look at your geodatabase and see if names have changed. In order to change the name of the actual feature class, you're going to do a little more work. Take a look Rename—Data Management toolbox | Documentation and see where that takes you.

nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

Using Python Dictionaries to Change Feature Class Names

NataliaGutierrez1

Hello!

I recently posted a question about python dictionaries and here I am again struggling with them..

I am now trying to use them to change feature class names.

Problem:

I have a list of 77 feature classes and I need to change their names from codes to names using a python dictionary.

For example:

Feature class name: T14_single_points

New name that I need: Alachua

I am not getting any errors when running this code but I am not getting any results either.

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

<SPAN class="comment token"># script to change fc name using a dictionary</SPAN>

arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>workspace <SPAN class="operator token">=</SPAN> r<SPAN class="string token">"D:\APRX_MXDS\USA_Parcels_2019_Project\test.gdb"</SPAN>
arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>overwriteOutput <SPAN class="operator token">=</SPAN> <SPAN class="token boolean">True</SPAN>

fc_list <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>ListFeatureClasses<SPAN class="punctuation token">(</SPAN><SPAN class="string token">"points*"</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># list of fc that end with points</SPAN>

<SPAN class="comment token"># dictionary</SPAN>
county_codes <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</SPAN><SPAN class="number token">14</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"Bradford"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">15</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"Brevard"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">16</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"Broward"</SPAN><SPAN class="punctuation token">}</SPAN>

<SPAN class="keyword token">for</SPAN> fc <SPAN class="keyword token">in</SPAN> fc_list<SPAN class="punctuation token">:</SPAN> <SPAN class="comment token"># loop through the feature classes</SPAN>
    key <SPAN class="operator token">=</SPAN> <SPAN class="string token">"{[1:3]}"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>fc<SPAN class="punctuation token">.</SPAN>name<SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># let the second and third characters in the fc name be the key</SPAN>
    <SPAN class="keyword token">if</SPAN> key <SPAN class="keyword token">in</SPAN> county_codes<SPAN class="punctuation token">:</SPAN> 
        fc <SPAN class="operator token">=</SPAN> county_codes<SPAN class="punctuation token">.</SPAN>get<SPAN class="punctuation token">(</SPAN>key<SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># assign the value in the dictionary as the new feature class name‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍</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>

thank you!

Find more posts tagged with

Accepted answers

JoeBorgione

I thought that was what you might be thinking. Take a step back and study your code for a minute, and ask yourself, what exactly is fc?

It's just a variable and the value of that variable changes as the for loop progresses. Run the snippet of code:

<SPAN class="keyword token">for</SPAN> fc <SPAN class="keyword token">in</SPAN> fc_list<SPAN class="punctuation token">:</SPAN> 
    key <SPAN class="operator token">=</SPAN> <SPAN class="string token">"{[1:3]}"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>fc<SPAN class="punctuation token">.</SPAN>name<SPAN class="punctuation token">)</SPAN> 
    <SPAN class="keyword token">if</SPAN> key <SPAN class="keyword token">in</SPAN> county_codes<SPAN class="punctuation token">:</SPAN>
        <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN>fc<SPAN class="punctuation token">)</SPAN> 
        fc <SPAN class="operator token">=</SPAN> county_codes<SPAN class="punctuation token">.</SPAN>get<SPAN class="punctuation token">(</SPAN>key<SPAN class="punctuation token">)</SPAN>
        <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN>fc<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>

And when it's done, take a look at your geodatabase and see if names have changed.

In order to change the name of the actual feature class, you're going to do a little more work. Take a look Rename—Data Management toolbox | Documentation and see where that takes you.

All comments

NataliaGutierrez1

Thank you Joe. As I told Dan, your answers will guide me for the next time I have to work on something similar. In the end I had to do it manually because it was taking me too long to automate it.

NataliaGutierrez1

Thank you Dan. In the end I had to do some more research on the topic before I was able to automate this.

Because I needed this very urgent I decided to do it manually since it was taking me to long to automate.

I am using your answer as a guide for the next time I have to do something similar.

DanPatterson_Retired

You are looking for the values, not the keys, which could be the other part of the problem.

Examine the example. Dictionaries are designed to be key-driven... your driver is 2 letters from your county names... aka, the values. There is a workaround, if you must stick to dictionaries.

codes <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</SPAN><SPAN class="number token">14</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"Bradford"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">15</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"Brevard"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">16</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"Broward"</SPAN><SPAN class="punctuation token">}</SPAN>
kys <SPAN class="operator token">=</SPAN> codes<SPAN class="punctuation token">.</SPAN>keys<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN>
vals <SPAN class="operator token">=</SPAN> codes<SPAN class="punctuation token">.</SPAN>values<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN>
v <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>v<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="number token">3</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="keyword token">for</SPAN> v <SPAN class="keyword token">in</SPAN> vals<SPAN class="punctuation token">]</SPAN>

kys  <SPAN class="comment token"># ---- dict_keys([14, 15, 16])</SPAN>
vals <SPAN class="comment token"># ---- dict_values(['Bradford', 'Brevard', 'Broward'])</SPAN>
v    <SPAN class="comment token"># ---- ['ra', 're', 'ro']</SPAN>

look_for <SPAN class="operator token">=</SPAN> <SPAN class="string token">'ra'</SPAN>  <SPAN class="comment token"># ---- Let's look for Bradford, ie, 'ra'</SPAN>

<SPAN class="keyword token">for</SPAN> k<SPAN class="punctuation token">,</SPAN> v <SPAN class="keyword token">in</SPAN> codes<SPAN class="punctuation token">.</SPAN>items<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
    <SPAN class="keyword token">if</SPAN> look_for <SPAN class="keyword token">in</SPAN> v<SPAN class="punctuation token">:</SPAN>
        <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"found look_for"</SPAN><SPAN class="punctuation token">)</SPAN>
    <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
        <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"keep looking"</SPAN><SPAN class="punctuation token">)</SPAN>
        
found look_for
keep looking
keep looking<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>

Of course you can skip the dictionary thing and just use nested lists

l <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">14</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Bradford'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="number token">15</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Brevard'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="number token">16</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Broward'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN>

look_for <SPAN class="operator token">=</SPAN> <SPAN class="string token">'ra'</SPAN>
<SPAN class="keyword token">for</SPAN> k<SPAN class="punctuation token">,</SPAN> v <SPAN class="keyword token">in</SPAN> l<SPAN class="punctuation token">:</SPAN>
    <SPAN class="keyword token">if</SPAN> look_for <SPAN class="keyword token">in</SPAN> v<SPAN class="punctuation token">:</SPAN>
        <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"found {}"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>v<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN>
    <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
        <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"keep looking"</SPAN><SPAN class="punctuation token">)</SPAN>
        
found Bradford
keep looking
keep looking<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>

And numpy structured arrays are my preference because slicing is enhanced and the operation can be vectorized on whole inputs columns rather than by row... but I will leave that since I am not sure where you are going with this.

DanPatterson_Retired

Natalia Gutierrez With that part resolved... what now remains?

JoeBorgione

I thought that was what you might be thinking. Take a step back and study your code for a minute, and ask yourself, what exactly is fc?

It's just a variable and the value of that variable changes as the for loop progresses. Run the snippet of code:

<SPAN class="keyword token">for</SPAN> fc <SPAN class="keyword token">in</SPAN> fc_list<SPAN class="punctuation token">:</SPAN> 
    key <SPAN class="operator token">=</SPAN> <SPAN class="string token">"{[1:3]}"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>fc<SPAN class="punctuation token">.</SPAN>name<SPAN class="punctuation token">)</SPAN> 
    <SPAN class="keyword token">if</SPAN> key <SPAN class="keyword token">in</SPAN> county_codes<SPAN class="punctuation token">:</SPAN>
        <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN>fc<SPAN class="punctuation token">)</SPAN> 
        fc <SPAN class="operator token">=</SPAN> county_codes<SPAN class="punctuation token">.</SPAN>get<SPAN class="punctuation token">(</SPAN>key<SPAN class="punctuation token">)</SPAN>
        <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN>fc<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>

And when it's done, take a look at your geodatabase and see if names have changed.

In order to change the name of the actual feature class, you're going to do a little more work. Take a look Rename—Data Management toolbox | Documentation and see where that takes you.

NataliaGutierrez1

Thank you Dan that was part of the problem

NataliaGutierrez1

Hi Joe, I thought I was renaming in the last line of my script. Line # 15. I guess I am really lost with this one...

JoeBorgione

Hello Natalia Gutierrez- to add to Dan Patterson's comments; I don't see you renaming anything, or is that the next stage in your script?

DanPatterson_Retired

<SPAN class="keyword token">if</SPAN> len<SPAN class="punctuation token">(</SPAN>fc_list<SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">==</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">:</SPAN>
    <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"something is wrong"</SPAN><SPAN class="punctuation token">)</SPAN>‍‍
<SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
    <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"processing stuff"</SPAN><SPAN class="punctuation token">)</SPAN>‍‍‍‍<SPAN class="string token">"points*"</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># list of fc that end with points</SPAN>

could be the issue

wild_card

Limits the results returned. If a value is not specified, all values are returned. The wildcard is not case sensitive.

Symbol	Description	Example
*	Represents zero or more characters.	Te* finds Tennessee and Texas.

did you mean

<SPAN class="" style="color: slategray; border: 0px; font-weight: inherit;">list of fc that <STRONG>begins</STRONG> with points</SPAN>

or did you mean

<SPAN class="" style="color: #669900; border: 0px; font-weight: inherit;">"*points"</SPAN><SPAN class="" style="color: #999999; border: 0px; font-weight: inherit;">)</SPAN> <SPAN class="" style="color: slategray; border: 0px; font-weight: inherit;"># list of fc that end with points</SPAN>

in any event that might account for one instance where nothing is processed.

Join the Conversation

Signed in members can post, follow updates, and more. New here? Register a free account.

Quick Links

Community Help
Find useful guides, FAQs, and documents to help you navigate and make the most of Esri Community.