topic Re: loop through a layer and select each polygon and save as jpeg in ArcMap in Python Questions

loop through a layer and select each polygon and save as jpeg in ArcMap

Official4 — Thu, 24 Dec 2020 16:07:11 GMT

I'm a beginner in ArcPy and I want to perform some tasks using ArcPy but I am not getting results.

I have a layer named survey in my current MXD and I want to select each polygon in surveyand export to JPEG and this is my script:

mxd = arcpy.mapping.MapDocument("CURRENT") 
df = arcpy.mapping.ListDataFrames(mxd)[0]
titleElement = arcpy.mapping.ListLayoutElements(mxd, "TEXT_ELEMENT")

rows = arcpy.SearchCursor("survey selection")
for row in rows: 
    titleElement = row.VendorFarm 
    query = '"FID"=' + str(row.FID)    
    arcpy.SelectLayerByAttribute_management("survey selection", "NEW_SELECTION", query)     
    df.zoomToSelectedFeatures()      
    arcpy.RefreshActiveView()

del rows 
del row

Re: loop through a layer and select each polygon and save as jpeg in ArcMap

DavidPike — Thu, 24 Dec 2020 16:56:09 GMT

You just need to throw in ExportToJPEG—Help | ArcGIS for Desktop within the loop (after refreshactiveview).

do something like concatenate an outpath with what you have already - str(row.FID)

I'd recommend using the arcpy.da cursor rather than the arcpy cursor.

SearchCursor—Help | ArcGIS for Desktop

It will require some change of syntax, though if you plan on working with cursors again, it's best to adopt the da cursor from the onset.

Re: loop through a layer and select each polygon and save as jpeg in ArcMap

RandyBurton — Wed, 30 Dec 2020 02:16:09 GMT

As @DavidPike suggests, you should use the da.SearchCursor. I noticed that you are attempting to access and set a map title using ListLayoutElements . This will return a list, and you will need to access the proper text element. It might be easier if you use the dynamic map "Title" as this property can be accessed and changed. Here's a code snippet which illustrates these ideas. Since it looks like you are using shape files, you may need to make some changes.

mxd = arcpy.mapping.MapDocument("CURRENT") df = arcpy.mapping.ListDataFrames(mxd)[0] feature = 'survey selection' fields = ['OID@', 'VendorFarm'] # OID@ is ObjectID token (see search cursor help) jpgPath = r"C:\Path\For\JPGs" # save location for jpgs # clear any existing selections arcpy.SelectLayerByAttribute_management(feature, "CLEAR_SELECTION") with arcpy.da.SearchCursor(feature, fields) as cursor: for FID, VendorFarm in cursor: # unpack each row by assigning to field name variables mxd.title = VendorFarm query = '"FID" = {}'.format(str(FID)) arcpy.SelectLayerByAttribute_management(feature, "NEW_SELECTION", query) df.zoomToSelectedFeatures() arcpy.RefreshActiveView() jpg = "{}\\{}.jpg".format(jpgPath, VendorFarm) # assuming VendorFarm is valid filename arcpy.mapping.ExportToJPEG (mxd, jpg)

If you need to use the ListLayoutElements, I would suggest that your map's text elements be named as this will help you find the correct element. Just a rough code snippet to illustrate:

titleElement = arcpy.mapping.ListLayoutElements(mxd, "TEXT_ELEMENT") for t in titleElement: if t.name == 'MapTitle' t.text = 'Some New Text'

Hope this helps.