Get attributes from many feature classes?

Question

I have a very large .gdb (15000+ geodatabase feature classes). I know that's unusually and impractically large, but it's the result of an iterative model, which ran through every block group in NY State to calculate residential percentage based on tax parcel data. Each feature class now has one attribute -its residential percentage.

I now need a table with all of those feature classes' attributes so that I can plug the residential percentages in to an Excel document I have. Normally I would merge them and export to Excel, but of course that's not possible with such a huge .gdb.

What other way can I do this? Is there some way to derive a table from the geodatabase itself?

Answer 1

You could use python to create a csv. You would need to change the variables to match your situation. This will produce a CSV with two columns: feature class name & the value of each row of the given column(field) name. This assumes the schema is identical for each feature class.

Thanks to Greg for his answer regarding list flattening: https://stackoverflow.com/a/952943/994972

Environment: ArcGIS Desktop 10.3.1 (Advanced License) Python 2.7

import arcpy
import csv
import operator

arcpy.env.workspace = "C:/Users/You/Desktop/Test.gdb"
newCSV = "C:/Users/You/Desktop/TESTCSV.csv"
valueList = []
fieldname ="YourFieldName"

for fc in arcpy.ListFeatureClasses():

    #Will add a list holding your feature class name and the value in the     field
    #example: [featureclassNameXXX,0.34]
    valueList.append([[fc,item[0]] for item in arcpy.da.SearchCursor(fc,fieldname)])
    #merge lists of lists
    flattenList =  reduce(operator.add,valueList)


with open(newCSV,'wb') as csvfile:

    writer = csv.writer(csvfile)
    writer.writerows(flattenList)

---

Output: Two column CSV with feature class name and desired value from each.