Hi, I am looking for some help on proper syntax in ArcGIS Pro/ Python 3. I am trying to read data from a feature class and write to another feature class. The attribute fields are different so I am reading from source and assigning it to output. I get this error at insertCursor.insertRow(newRow). Appreciate any input. Thanks def LoadData(fSource, fTarget): # setup search cursor fields = [ '*' ] fldShape = "SHAPE@" # target field mapping fldCountry = 'Country' fldCommodity = "Product" constructionYear = "CNSTR_YEAR" try : with arcpy.da.InsertCursor(fTarget, [ '*' ]) as insertCursor: with arcpy.da.SearchCursor(fSource, "*" ) as cursor: for row in cursor: country = row[cursor.fields.index(fldCountry)] geometry = row[cursor.fields.index(fldShape)] commodity = row[cursor.fields.index(fldCommodity)] constructionYear = row[cursor.fields.index(constructionYear)] newRow = [country, geometry, commodity, constructionYear] insertCursor.insertRow(newRow) except Exception: print(e.args[ 0 ])

I need a bit more information on the calculation. But I would add a field to a targetField list. Then do the calculation just before the insert row. The idea would be something like this, but the code is untested and needs modification to do the calculation. fSource = '' # some source fTarget = '' # the target sourceFields = [ 'SHAPE@' , 'Country' , 'Product' , 'CNSTR_YEAR' ] targetFields = [ 'SHAPE@' , 'Country' , 'Product' , 'CNSTR_YEAR' , 'CalcField' ] # add calculated field with with arcpy . da . InsertCursor ( fTarget , targetFields ) as insertCursor : with arcpy . da . SearchCursor ( fSource , sourceFields ) as cursor : for row in cursor : newRow = list ( row ) # get sourceField values x = 5 + 2 # some calculation newRow . append ( x ) # append calculation to end insertCursor . insertRow ( newRow ) # insert newRow to fTarget

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sequence size must match size of the row

jayshukla

Hi, I am looking for some help on proper syntax in ArcGIS Pro/ Python 3. I am trying to read data from a feature class and write to another feature class. The attribute fields are different so I am reading from source and assigning it to output. I get this error at insertCursor.insertRow(newRow).

Appreciate any input.
Thanks

<SPAN class="" style="color: var(--highlight-comment); border: 0px; font-weight: inherit; font-size: 13px;">def LoadData(fSource, fTarget):
# setup search cursor</SPAN>fields = [<SPAN class="" style="color: var(--highlight-variable); border: 0px; font-weight: inherit; font-size: 13px;">'*'</SPAN>]  fldShape = <SPAN class="" style="color: var(--highlight-variable); border: 0px; font-weight: inherit; font-size: 13px;">"SHAPE@"</SPAN><SPAN class="" style="color: var(--highlight-comment); border: 0px; font-weight: inherit; font-size: 13px;"># target field mapping </SPAN>fldCountry = <SPAN class="" style="color: var(--highlight-variable); border: 0px; font-weight: inherit; font-size: 13px;">'Country'</SPAN>fldCommodity = <SPAN class="" style="color: var(--highlight-variable); border: 0px; font-weight: inherit; font-size: 13px;">"Product"</SPAN>constructionYear = <SPAN class="" style="color: var(--highlight-variable); border: 0px; font-weight: inherit; font-size: 13px;">"CNSTR_YEAR"</SPAN><SPAN class="" style="color: var(--highlight-keyword); border: 0px; font-weight: inherit; font-size: 13px;">try</SPAN>:      <SPAN class="" style="color: var(--highlight-keyword); border: 0px; font-weight: inherit; font-size: 13px;">with</SPAN> arcpy.da.InsertCursor(fTarget, [<SPAN class="" style="color: var(--highlight-variable); border: 0px; font-weight: inherit; font-size: 13px;">'*'</SPAN>]) <SPAN class="" style="color: var(--highlight-keyword); border: 0px; font-weight: inherit; font-size: 13px;">as</SPAN> insertCursor:         <SPAN class="" style="color: var(--highlight-keyword); border: 0px; font-weight: inherit; font-size: 13px;">with</SPAN> arcpy.da.SearchCursor(fSource, <SPAN class="" style="color: var(--highlight-variable); border: 0px; font-weight: inherit; font-size: 13px;">"*"</SPAN>) <SPAN class="" style="color: var(--highlight-keyword); border: 0px; font-weight: inherit; font-size: 13px;">as</SPAN> cursor:             <SPAN class="" style="color: var(--highlight-keyword); border: 0px; font-weight: inherit; font-size: 13px;">for</SPAN> row <SPAN class="" style="color: var(--highlight-keyword); border: 0px; font-weight: inherit; font-size: 13px;">in</SPAN> cursor:                 country = row[cursor.fields.index(fldCountry)]                 geometry = row[cursor.fields.index(fldShape)]                 commodity = row[cursor.fields.index(fldCommodity)]                 constructionYear = row[cursor.fields.index(constructionYear)]                                  newRow = [country, geometry, commodity, constructionYear]                  insertCursor.insertRow(newRow)  <SPAN class="" style="color: var(--highlight-keyword); border: 0px; font-weight: inherit; font-size: 13px;">except</SPAN> Exception:         print(e.args[<SPAN class="" style="color: var(--highlight-namespace); border: 0px; font-weight: inherit; font-size: 13px;">0</SPAN>])

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Accepted answers

RandyBurton

I need a bit more information on the calculation. But I would add a field to a targetField list. Then do the calculation just before the insert row. The idea would be something like this, but the code is untested and needs modification to do the calculation.

fSource <SPAN class="operator token">=</SPAN> <SPAN class="string token">''</SPAN> <SPAN class="comment token"># some source</SPAN>
fTarget <SPAN class="operator token">=</SPAN> <SPAN class="string token">''</SPAN> <SPAN class="comment token"># the target</SPAN>

sourceFields <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'SHAPE@'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Country'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Product'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'CNSTR_YEAR'</SPAN><SPAN class="punctuation token">]</SPAN> 
targetFields <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'SHAPE@'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Country'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Product'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'CNSTR_YEAR'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'CalcField'</SPAN> <SPAN class="punctuation token">]</SPAN> <SPAN class="comment token"># add calculated field</SPAN>

<SPAN class="keyword token">with</SPAN> <SPAN class="keyword token">with</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>InsertCursor<SPAN class="punctuation token">(</SPAN>fTarget<SPAN class="punctuation token">,</SPAN> targetFields<SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">as</SPAN> insertCursor<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>fSource<SPAN class="punctuation token">,</SPAN> sourceFields<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>
            newRow <SPAN class="operator token">=</SPAN> list<SPAN class="punctuation token">(</SPAN>row<SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># get sourceField values</SPAN>
            x <SPAN class="operator token">=</SPAN> <SPAN class="number token">5</SPAN><SPAN class="operator token">+</SPAN><SPAN class="number token">2</SPAN> <SPAN class="comment token"># some calculation</SPAN>
            newRow<SPAN class="punctuation token">.</SPAN>append<SPAN class="punctuation token">(</SPAN>x<SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># append calculation to end</SPAN>
            insertCursor<SPAN class="punctuation token">.</SPAN>insertRow<SPAN class="punctuation token">(</SPAN>newRow<SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># insert newRow to fTarget‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍</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>

All comments

JoshuaBixby

The sequence size error is saying you are either trying to insert fewer or more items into a record than what the cursor is set up for. Since you are using "*" for the fields, which by the way is a poor practice, I can't say for sure what is going wrong with the fields.

DanPatterson

This would help with reading

/blogs/dan_patterson/2016/08/14/script-formatting

jayshukla

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">LoadData</SPAN><SPAN class="punctuation token">(</SPAN>fSource<SPAN class="punctuation token">,</SPAN> fTarget<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>

  <SPAN class="comment token"># setup search cursor</SPAN>
fields <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'*'</SPAN><SPAN class="punctuation token">]</SPAN>

fldShape <SPAN class="operator token">=</SPAN> <SPAN class="string token">"SHAPE@"</SPAN>

<SPAN class="comment token"># target field mapping</SPAN>
fldCountry <SPAN class="operator token">=</SPAN> <SPAN class="string token">'Country'</SPAN>
fldCommodity <SPAN class="operator token">=</SPAN> <SPAN class="string token">"Product"</SPAN>
constructionYear <SPAN class="operator token">=</SPAN> <SPAN class="string token">"CNSTR_YEAR"</SPAN>

<SPAN class="keyword token">try</SPAN><SPAN class="punctuation token">:</SPAN>
<SPAN class="keyword token">with</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>InsertCursor<SPAN class="punctuation token">(</SPAN>fTarget<SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'*'</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">as</SPAN> insertCursor<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>fSource<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"*"</SPAN><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>
  country <SPAN class="operator token">=</SPAN> row<SPAN class="punctuation token">[</SPAN>cursor<SPAN class="punctuation token">.</SPAN>fields<SPAN class="punctuation token">.</SPAN>index<SPAN class="punctuation token">(</SPAN>fldCountry<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN>
geometry <SPAN class="operator token">=</SPAN> row<SPAN class="punctuation token">[</SPAN>cursor<SPAN class="punctuation token">.</SPAN>fields<SPAN class="punctuation token">.</SPAN>index<SPAN class="punctuation token">(</SPAN>fldShape<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN>
commodity <SPAN class="operator token">=</SPAN> row<SPAN class="punctuation token">[</SPAN>cursor<SPAN class="punctuation token">.</SPAN>fields<SPAN class="punctuation token">.</SPAN>index<SPAN class="punctuation token">(</SPAN>fldCommodity<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN>
constructionYear <SPAN class="operator token">=</SPAN> row<SPAN class="punctuation token">[</SPAN>cursor<SPAN class="punctuation token">.</SPAN>fields<SPAN class="punctuation token">.</SPAN>index<SPAN class="punctuation token">(</SPAN>constructionYear<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN>

newRow <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>country<SPAN class="punctuation token">,</SPAN> geometry<SPAN class="punctuation token">,</SPAN> commodity<SPAN class="punctuation token">,</SPAN> constructionYear<SPAN class="punctuation token">]</SPAN>

insertCursor<SPAN class="punctuation token">.</SPAN>insertRow<SPAN class="punctuation token">(</SPAN>newRow<SPAN class="punctuation token">)</SPAN>

<SPAN class="keyword token">except</SPAN> Exception<SPAN class="punctuation token">:</SPAN>
  <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN>e<SPAN class="punctuation token">.</SPAN>args<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><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>

jayshukla

Thanks Joshua, I will try limiting the fields and see it helps.

jayshukla

This looks better formatting, Thanks Dan for pointing this out.

RandyBurton

As Joshua Bixby‌ states, using a wildcard for the fields is a bad idea. In your case, you cannot be sure the order you are assembling the row matches the order the data was selected. Also, for testing you should avoid a try/except block so the error messages will be clear and you can see what exceptions you may need to guard against.

Can we assume that the field names are identical (as well as field type and length) between the source and target features? If so, you might test the following with copies of your data:

fSource = '' # some source
fTarget = '' # the target

fields = ['SHAPE@', 'Country', 'Product', 'CNSTR_YEAR'] # assuming same name used in both target/source

with with arcpy.da.InsertCursor(fTarget, fields) as insertCursor:
    with arcpy.da.SearchCursor(fSource, fields) as cursor:
        for row in cursor:
            insertCursor.insertRow(row)
‍‍‍‍‍‍‍‍‍<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>

jayshukla

Thanks Randy, Your code works great. I have one calculated value that doesn't exist in source data, how do I update that field in target using this construct.

RandyBurton

fSource <SPAN class="operator token">=</SPAN> <SPAN class="string token">''</SPAN> <SPAN class="comment token"># some source</SPAN>
fTarget <SPAN class="operator token">=</SPAN> <SPAN class="string token">''</SPAN> <SPAN class="comment token"># the target</SPAN>

sourceFields <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'SHAPE@'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Country'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Product'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'CNSTR_YEAR'</SPAN><SPAN class="punctuation token">]</SPAN> 
targetFields <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN><SPAN class="string token">'SHAPE@'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Country'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'Product'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'CNSTR_YEAR'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'CalcField'</SPAN> <SPAN class="punctuation token">]</SPAN> <SPAN class="comment token"># add calculated field</SPAN>

<SPAN class="keyword token">with</SPAN> <SPAN class="keyword token">with</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>da<SPAN class="punctuation token">.</SPAN>InsertCursor<SPAN class="punctuation token">(</SPAN>fTarget<SPAN class="punctuation token">,</SPAN> targetFields<SPAN class="punctuation token">)</SPAN> <SPAN class="keyword token">as</SPAN> insertCursor<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>fSource<SPAN class="punctuation token">,</SPAN> sourceFields<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>
            newRow <SPAN class="operator token">=</SPAN> list<SPAN class="punctuation token">(</SPAN>row<SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># get sourceField values</SPAN>
            x <SPAN class="operator token">=</SPAN> <SPAN class="number token">5</SPAN><SPAN class="operator token">+</SPAN><SPAN class="number token">2</SPAN> <SPAN class="comment token"># some calculation</SPAN>
            newRow<SPAN class="punctuation token">.</SPAN>append<SPAN class="punctuation token">(</SPAN>x<SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># append calculation to end</SPAN>
            insertCursor<SPAN class="punctuation token">.</SPAN>insertRow<SPAN class="punctuation token">(</SPAN>newRow<SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># insert newRow to fTarget‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍</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>

jayshukla

Thanks Randy, Joshua for your help on this. this works like a charm, really appreciate your help on this.

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