ArcPy.Mapping Module Makes Complex PDF Creation Easy

Recently, I was presented with a problem that was a perfect opportunity for trying out ESRI's ArcPy Python site package. We have a series of map documents that are set up with Data Driven Pages to export various maps for each of the counties of Utah. Each mxd had a different theme. The goal was to develop a script that would export all of the Data Driven Pages for each mxd and then combine them by county. After a few hours of work I had 72 lines of code that did just that. Here's what I came up with:

I used only two modules for this script: arcpy.mapping and os (great for working with the file system).

# import modules
import arcpy.mapping, os

# variables
baseFolder = os.getcwd() # current working directory
outputFolder = baseFolder + r'\PDFs'

The os module was great for deleting the old files and getting a list of the map documents.

# clear out old pdfs
print '\nDeleting old PDFs...'
oldPDFs = os.listdir(outputFolder)
for f in oldPDFs:
    os.remove(outputFolder + '\\' + f)

# get list of all files in the folder
print '\nGetting list of mxds...'
allItems = os.listdir(baseFolder)
# filter out just .mxd's
mxdFileNames = [(x) for x in allItems if x.endswith('.mxd')]
mxdFileNames.sort()

The DataDrivenPages class was the key class in the ArcPy.Mapping module for this script. It is obtained through the MapDocument class. Here I start to loop through the mxd's and get a reference to the DataDrivenPages object that I am interested in.

# loop through mxds
for name in mxdFileNames:
    print '\nProcessing: ' + name
    
    # get mxd
    mxd = arcpy.mapping.MapDocument(baseFolder + '\\' + name)
    
    # get datadrivenpages object
    ddp = mxd.dataDrivenPages

Once I've got the DataDrivenPages object, then I start to loop through all of the pages.

    # loop through pages
    pg = 1
    while pg <= ddp.pageCount:
        # change current page
        ddp.currentPageID = pg
        
        # get name of current page
        name = ddp.pageRow.getValue('NAME')
        print name

Before I export the page, I check to see if there is already an existing pdf for that particular county. If there is I export the page to a temp PDF file and then use the PDFDocument::appendPages() function to add it to the existing PDF. If not, then I just export it out to a new PDF.

        # check to see if there is already a pdf file created for this county
        pdfFile = outputFolder + '\\' + name + '.pdf' 
        if os.path.exists(pdfFile):
            print 'Existing pdf found. Appending...'
            
            # open PDF document
            pdf = arcpy.mapping.PDFDocumentOpen(pdfFile)
            
            # output to temporary file
            tempFile = outputFolder + '\\temp.pdf'
            ddp.exportToPDF(tempFile, 'CURRENT')
            
            # append to existing file
            pdf.appendPages(tempFile)
            
            # delete temp file
            os.remove(tempFile)
            
            # clean up variables
            del pdf
            
        else: # file does not exist, export to new file
            print 'No existing pdf found. Exporting to new pdf.'
            ddp.exportToPDF(pdfFile, 'CURRENT')
        
        # increment page number
        pg = pg + 1

Then, all that's left if a little clean up.

    # clean up variables
    del mxd, ddp
    
raw_input('Done. Press any key to exit...')

And that's it! Here's the entire script and an example output pdf.