Newbie here. I'm self-teaching about cursors and am practicing on this dataset. "testclass" is a feature class with an ID field (6 digit integer) and a name field. I want to go through and assign a unique name based on the ID. The following code works and illustrates more or less what I am trying to do (although I am sure it gives many of you heartburn with how clunky it is-- sorry ). point = "testclass" update = arcpy . da . UpdateCursor ( point , [ "ID" , "name" ] ) for row in update : ID = row [ 0 ] if ( ID == '174769' ) : name = "R4S8f" row [ 1 ] = name elif ( ID == '174771' ) : name = "C3F8m" row [ 1 ] = name elif ( ID == '174773' ) : name = "F4S8m" row [ 1 ] = name elif ( ID == '174774' ) : name = "C1S8f" row [ 1 ] = name elif ( ID == '174776' ) : name = "F3S8f" row [ 1 ] = name elif ( ID == '174778' ) : name = "R1S8f" row [ 1 ] = name elif ( ID == '174781' ) : name = "R6F8f" row [ 1 ] = name update . updateRow ( row ) I would like to take this same concept and use an update cursor with a dictionary. I've found several posts online so I think I'm close but I can't quite get the syntax. This is what I have. assignName = { 174769 : 'R4S8f' , 174771 : 'C3F8m' , 174773 : 'F4S8m' , 174774 : 'C1S8f' , 174776 : 'F3S8f' , 174778 : 'R1S8f' , 174781 : 'R6F8f' } cursor = arcpy . da . UpdateCursor ( 'testclass' , [ "ID" , "name" ] ) for row in cursor : if row . ID in assignName : updateRow . name = assignName [ updateRow . ID ] update . updateRow ( row ) It's telling me in line 7 "'list' object has no attribute 'ID'" when I run this in ArcGIS Pro. Thanks in advance

As I mentioned back in March, if your code isn't generating any errors, then Line 02 is never evaluating to True because Line 03 will generate a TypeError if it ever gets called. >> > row = [ 'foo' , 'bar' ] >> > assignName = { 'foo' : 'hi' , 'bar' : 'bye' } >> > >> > assignName ( row [ 0 ] ) Runtime error Traceback ( most recent call last ) : File " " , line 1 , in module > TypeError : 'dict' object is not callable >> > Also, as Randy Burton mentioned in March, you look up values in dictionaries by using square brackets and not parentheses: >> > row = [ 'foo' , 'bar' ] >> > assignName = { 'foo' : 'hi' , 'bar' : 'bye' } >> > assignName ( 'foo' ) >> > >> > assignName [ row [ 0 ] ] 'hi' >> >

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How to use update cursor with a dictionary?

RyanHowell1

Newbie here.

I'm self-teaching about cursors and am practicing on this dataset. "testclass" is a feature class with an ID field (6 digit integer) and a name field. I want to go through and assign a unique name based on the ID. The following code works and illustrates more or less what I am trying to do (although I am sure it gives many of you heartburn with how clunky it is-- sorry ).

point <SPAN class="operator token">=</SPAN> <SPAN class="string token">"testclass"</SPAN>
update <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>UpdateCursor<SPAN class="punctuation token">(</SPAN>point<SPAN class="punctuation token">,</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="string token">"ID"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"name"</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN>

<SPAN class="keyword token">for</SPAN> row <SPAN class="keyword token">in</SPAN> update<SPAN class="punctuation token">:</SPAN>
    ID <SPAN class="operator token">=</SPAN> row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN>
    <SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">(</SPAN>ID <SPAN class="operator token">==</SPAN> <SPAN class="string token">'174769'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
        name <SPAN class="operator token">=</SPAN> <SPAN class="string token">"R4S8f"</SPAN>
        row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> name
    <SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">(</SPAN>ID <SPAN class="operator token">==</SPAN> <SPAN class="string token">'174771'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
        name <SPAN class="operator token">=</SPAN> <SPAN class="string token">"C3F8m"</SPAN>
        row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> name
    <SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">(</SPAN>ID <SPAN class="operator token">==</SPAN> <SPAN class="string token">'174773'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
        name <SPAN class="operator token">=</SPAN> <SPAN class="string token">"F4S8m"</SPAN>
        row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> name
    <SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">(</SPAN>ID <SPAN class="operator token">==</SPAN> <SPAN class="string token">'174774'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
        name <SPAN class="operator token">=</SPAN> <SPAN class="string token">"C1S8f"</SPAN>
        row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> name
    <SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">(</SPAN>ID <SPAN class="operator token">==</SPAN> <SPAN class="string token">'174776'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
        name <SPAN class="operator token">=</SPAN> <SPAN class="string token">"F3S8f"</SPAN>
        row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> name
    <SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">(</SPAN>ID <SPAN class="operator token">==</SPAN> <SPAN class="string token">'174778'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
        name <SPAN class="operator token">=</SPAN> <SPAN class="string token">"R1S8f"</SPAN>
        row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> name
    <SPAN class="keyword token">elif</SPAN> <SPAN class="punctuation token">(</SPAN>ID <SPAN class="operator token">==</SPAN> <SPAN class="string token">'174781'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
        name <SPAN class="operator token">=</SPAN> <SPAN class="string token">"R6F8f"</SPAN>
        row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> name

    update<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>‍</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>

I would like to take this same concept and use an update cursor with a dictionary. I've found several posts online so I think I'm close but I can't quite get the syntax. This is what I have.

assignName <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</SPAN><SPAN class="number token">174769</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'R4S8f'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">174771</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'C3F8m'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">174773</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'F4S8m'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">174774</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'C1S8f'</SPAN><SPAN class="punctuation token">,</SPAN>
              <SPAN class="number token">174776</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'F3S8f'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">174778</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'R1S8f'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">174781</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'R6F8f'</SPAN><SPAN class="punctuation token">}</SPAN>

cursor <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>UpdateCursor<SPAN class="punctuation token">(</SPAN><SPAN class="string token">'testclass'</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="string token">"ID"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"name"</SPAN><SPAN class="punctuation token">]</SPAN><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">if</SPAN> row<SPAN class="punctuation token">.</SPAN>ID <SPAN class="keyword token">in</SPAN> assignName<SPAN class="punctuation token">:</SPAN>
        updateRow<SPAN class="punctuation token">.</SPAN>name <SPAN class="operator token">=</SPAN> assignName<SPAN class="punctuation token">[</SPAN>updateRow<SPAN class="punctuation token">.</SPAN>ID<SPAN class="punctuation token">]</SPAN>
        update<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>

It's telling me in line 7 "'list' object has no attribute 'ID'" when I run this in ArcGIS Pro.

Thanks in advance

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DanPatterson_Retired

To be overt... see lines 8 and 12 in my example

RandyBurton

Try:

row[1] = assignName[row[0]] # to access dictionary, use square brackets not ()<SPAN class="line-numbers-rows"><SPAN>‍</SPAN></SPAN>

JoshuaBixby

I suspect your conditional check is never coming back True because the following

assignName<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="line-numbers-rows"><SPAN>‍</SPAN></SPAN>

<SPAN class=""><BR /></SPAN>

will generate a TypeError since dictionaries are not callable.

DanPatterson_Retired

I would throw some print statements in.

UpdateCursor—Data Access module | ArcGIS Desktop

assignName <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">{</SPAN><SPAN class="number token">174769</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'R4S8f'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">174771</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'C3F8m'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">174773</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'F4S8m'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">174774</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'C1S8f'</SPAN><SPAN class="punctuation token">,</SPAN>
              <SPAN class="number token">174776</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'F3S8f'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">174778</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'R1S8f'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">174781</SPAN> <SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'R6F8f'</SPAN><SPAN class="punctuation token">}</SPAN>

row0 <SPAN class="operator token">=</SPAN> <SPAN class="number token">174769</SPAN>

row0 <SPAN class="keyword token">in</SPAN> assignName
<SPAN class="token boolean">True</SPAN>

assignName<SPAN class="punctuation token">[</SPAN>row0<SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> <SPAN class="string token">'hello'</SPAN>

assignName

<SPAN class="punctuation token">{</SPAN><SPAN class="number token">174769</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'hello'</SPAN><SPAN class="punctuation token">,</SPAN>
 <SPAN class="number token">174771</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'C3F8m'</SPAN><SPAN class="punctuation token">,</SPAN>
 <SPAN class="number token">174773</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'F4S8m'</SPAN><SPAN class="punctuation token">,</SPAN>
 <SPAN class="number token">174774</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'C1S8f'</SPAN><SPAN class="punctuation token">,</SPAN>
 <SPAN class="number token">174776</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'F3S8f'</SPAN><SPAN class="punctuation token">,</SPAN>
 <SPAN class="number token">174778</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'R1S8f'</SPAN><SPAN class="punctuation token">,</SPAN>
 <SPAN class="number token">174781</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">'R6F8f'</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>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

RyanHowell1

Thanks for your input Dan. I've made those changes (and fixed a couple of other typos from switching around names I found) and now have the following. It runs without an error but doesn't update the table (the ID field is populated but the name is not).

<SPAN class="keyword token">for</SPAN> row <SPAN class="keyword token">in</SPAN> cursor<SPAN class="punctuation token">:</SPAN>
    <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">in</SPAN> assignName<SPAN class="punctuation token">:</SPAN>
        row<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> assignName<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>
        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>

I'm beginning to think I don't understand either dictionaries or update cursors as well as I thought I did.

DanPatterson_Retired

row has two entries, ["ID", "name"], you can slice, ie row[0] if you want the ID or row[1] if you want the name

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