Text Element Questions

GeoffOlson · ‎08-14-2013

So I've got my text element function working in layout view, but it leaves me with two questions. Can multiple rows be concatenated into the row.getValue or can it only find single fields? Also, is it possible to return all feature records?

Here is the script I'm using to get the first result to fill the text box:

import arcpy  mxd = arcpy.mapping.MapDocument("Current") mapLyr = arcpy.mapping.ListLayers(mxd, "Detail_2013")[0]  concatElem = arcpy.mapping.ListLayoutElements(mxd, "TEXT_ELEMENT", "concat")[0]  rows = arcpy.SearchCursor(mapLyr.dataSource) row = rows.next()  typeElem.text = row.getValue("CONCAT")  mxd.save() del mxd, row, rows,

Any suggestions a much appreciated.

T__WayneWhitley · ‎08-15-2013

I'm just thinking maybe the range function would apply here?

Since you know the total count couldn't you just run a loop, branching for the part of each half of the range?

In general, illustrated by:

>>> rowcount = 10
>>> for rows in range(rowcount):
 if rows in range(rowcount/2):
  print 'row ' + str(rows) + ' in range 1.'
 elif rows in range(rowcount/2, rowcount):
  print 'row ' + str(rows) + ' in range 2.'

  
row 0 in range 1.
row 1 in range 1.
row 2 in range 1.
row 3 in range 1.
row 4 in range 1.
row 5 in range 2.
row 6 in range 2.
row 7 in range 2.
row 8 in range 2.
row 9 in range 2.
>>>

MathewCoyle · ‎08-15-2013

I'm just thinking maybe the range function would apply here?

Yes that's a nice method when you know the number of columns. Would need a slight tweak for odd numbers of rows.

rowcount = 9
for rows in range(rowcount):
    if rows in range(rowcount / 2 + 1):
        print 'row ' + str(rows) + ' in range 1.'
    elif rows in range(rowcount / 2, rowcount):
        print 'row ' + str(rows) + ' in range 2.'

There was also this for a tool that can take a dynamic number of text columns (as long as they are already created and follow the naming/number convention).

import os
import arcpy


def main():

    layer_name = arcpy.GetParameterAsText(0)
    field = arcpy.GetParameterAsText(1)
    number_columns = float(arcpy.GetParameterAsText(2))

    mxd = arcpy.mapping.MapDocument("Current")
    mapLyr = arcpy.mapping.ListLayers(mxd, layer_name)[0]

    rowcount = int(arcpy.GetCount_management(layer_name).getOutput(0))
    percolumn = round(rowcount / number_columns)

    text_var = str()
    item_count = 0
    column_count = 1
    for row in arcpy.SearchCursor(mapLyr.dataSource, sort_fields='{0} A'.format(field)):
        text_var += '{0}{1}'.format(row.getValue(field), os.linesep)
        item_count += 1
        column = 'concat{0}'.format(column_count)
        arcpy.AddMessage(item_count)

        if item_count == percolumn and column_count != number_columns:
            arcpy.AddMessage('next column')
            arcpy.mapping.ListLayoutElements(mxd, "TEXT_ELEMENT", column)[0].text = text_var
            text_var = str()
            column_count += 1
            item_count = 0

    arcpy.mapping.ListLayoutElements(mxd, "TEXT_ELEMENT", column)[0].text = text_var

    arcpy.RefreshActiveView()
    mxd.save()
    del mxd

    arcpy.AddMessage("First column should have : {0} rows.".format(percolumn))  #used to check that it calculated properly

if __name__ == '__main__':
    main()

GeoffOlson · ‎08-16-2013

Thanks for all the help, guys! I have the if statement almost working. The second column works fine, but the first column is only returning the last result. I have a field that numbers each row in the table, besides the FID, so that way on each map page each row of text is numbered and it matches the label in the map. Instead of using a counter += 1, can an attribute field be used instead? I have the field "Crash_Num" that numbers each feature in the map for each page but I don't know how to use a searchcursor and getValue.

T__WayneWhitley · ‎08-16-2013

Are you using Mathew's code? (If so, you should award him points and/or the answer when you finally get things running.)

As 'extra' help, this is where the row from your table value for the 'field' is passed (from Mathew's last posted code):

for row in arcpy.SearchCursor(mapLyr.dataSource, sort_fields='{0} A'.format(field)):
        text_var += '{0}{1}'.format(row.getValue(field), os.linesep)

EDIT:
Actually, in that 1st line above, all your table fields are being passed in, just that the one specified as 'field' (assigned at the SetParam statement at the beginning) is used for sorting.

So you could 'look up' other field values by inserting a line within the loop such as:

aNewTxtVar = row.getValue('yourDesignatedFieldname')

(see getValue for the SearchCursor in the webhelp)
Anyway, hope that helps!

Enjoy,
Wayne

GeoffOlson · ‎08-16-2013

I think I just got it working. Here's the final script:

import arcpy, os

mxd = arcpy.mapping.MapDocument("Current")
mapLyr = arcpy.mapping.ListLayers(mxd, "Detail_2013")[0]

concatElem1 = arcpy.mapping.ListLayoutElements(mxd, "TEXT_ELEMENT", "concat1")[0]
concatElem2 = arcpy.mapping.ListLayoutElements(mxd, "TEXT_ELEMENT", "concat2")[0]

rowcount = int(arcpy.GetCount_management("Detail_2013").getOutput(0))
percolumn = round(rowcount / 2.0)
count1 = 1
count2 = rowcount

rows = arcpy.SearchCursor(mapLyr.dataSource)

text_var1 = str()
text_var2 = str()

for row in rows:
    if count1 <= percolumn:
        text_var1 += '{0}{1}'.format(row.getValue("CONCAT"), os.linesep)
        concatElem1.text = text_var1
        count1 += 1
    elif count2 > percolumn:
        text_var2 += '{0}{1}'.format(row.getValue("CONCAT"), os.linesep)
        concatElem2.text = text_var2
        count2 - 1
    else:
        pass
mxd.save()
del mxd, row, rows,

GeoffOlson · ‎08-16-2013

The only problem I have now is the script isn't following the page definition query. Only the queried features appear in the attribute table, but the script lists all features, even the ones that are queried out.

T__WayneWhitley · ‎08-16-2013

Well you have options - that's the good news. The searchcursor input parameter works on a layer (the 1st param)...or you could optionally enter a query filter...see the syntax and explanation at the link below:

usage:
SearchCursor (in_table, field_names, {where_clause}, {spatial_reference}, {explode_to_points}, {sql_clause})

http://resources.arcgis.com/en/help/main/10.1/index.html#//018w00000011000000

oops, that one was for the da (data access) search cursor.... you need this one:

SearchCursor (dataset, {where_clause}, {spatial_reference}, {fields}, {sort_fields})

http://resources.arcgis.com/en/help/main/10.1/index.html#//018v00000050000000

GeoffOlson · ‎08-16-2013

Using a SearchCursor should filter out which rows are being returned? Can multiple row.getValue functions be used? I was concerned the "for row from rows:" would have assigned a value to row and couldn't be used twice, and a different variable be created in place of row?

Manually setting a definition query also fails to limit which rows get searched.

T__WayneWhitley · ‎08-16-2013

You should post your code and any error msgs you're receiving...

In short, yes you can get another field value from the row object.
Incidentally, you could say 'for browncow in rows' and you are still implicitly getting a row object from the cursor. (why simply using 'row' is often used)

I suspect your where_clause query is faulty, but have no idea since there's no posted code, etc. Don't forget to post the error msg too!

GeoffOlson · ‎08-16-2013

I added this to get the page name:

pageNum = arcpy.GetParameterAsText(0)
ddp = mxd.dataDrivenPages
arcpy.AddMessage(pageNum)
pageID = mxd.dataDrivenPages.getPageIDFromName(str(pageNum))
mxd.dataDrivenPages.currentPageID = pageID

and I changed the SearchCursor to this:

rows = arcpy.SearchCursor(mapLyr.dataSource, "PageID = \'Intersec\'")

but I get an error saying the fields in the search cursor do not exits. I'm trying to set the field value to the page name. The other thing that happens is the page name seems to only be stored as a page number and not the specified index layer field.