topic Re: ListFields returning blanklist in Python Questions

ListFields returning blanklist

BlakeBarr — Sat, 11 Dec 2021 14:26:34 GMT

Hi Everyone, I am trying to convert dbf to csv using the following code:

import arcpy
import os
import csv


def DBFtoCSV(path):
    '''Convert every DBF table into CSV table.
    '''
    arcpy.env.workspace = path
    tablelist=arcpy.ListTables('*', 'dBASE')
    for table in tablelist:
        outputFile = '{}.csv'.format(table.split('.dbf')[0])
        # Get the fields in the dbf to use for the cursor and csv header row.
        fields = []
        for field in arcpy.ListFields(table):
            fields.append(str(field.name))


# Make the csv.
        with open((os.path.join(path,outputFile)),'wb') as output:
            dataWriter = csv.writer(output, delimiter=',', quotechar='"', quoting=csv.QUOTE_MINIMAL)


    # Write header row.
            dataWriter.writerow(fields)


    # Write each row of data to the csv.
            with arcpy.da.SearchCursor(table, fields) as cursor:
                for row in cursor:
                    dataWriter.writerow(row)


        print('Finished creating {}'.format(outputFile))
   


if __name__ == '__main__': 
    path=r'F:\DataLocation'
    DBFtoCSV(path)

I am getting an error at the SearchCursor because it says field names must be string or non empty. I added the print statement and it turns out my list of fields is empty. Can anyone tell me why this is?

Re: ListFields returning blanklist

DanPatterson_Retired — Tue, 26 Jul 2016 21:34:59 GMT

ListFields—Help | ArcGIS for Desktop

Can you format your code to make it easier to read. Also what is the table name when it prints?

Code Formatting... the basics++

Re: ListFields returning blanklist

DarrenWiens2 — Tue, 26 Jul 2016 21:40:17 GMT

Did you forget to include a real path?

path=r'path'

Re: ListFields returning blanklist

BlakeBarr — Tue, 26 Jul 2016 21:40:18 GMT

Thanks Dan,

I have formatted the code. When I print the table name it gives me "filename.dbf" The filename matches exactly with the name in the path directory.

Re: ListFields returning blanklist

BlakeBarr — Tue, 26 Jul 2016 21:41:56 GMT

Darren,

Thanks for checking. The actual code has the full path name spelled out, just put that there for privacy.

Re: ListFields returning blanklist

DanPatterson_Retired — Tue, 26 Jul 2016 21:42:14 GMT

I suspect it can't find a file, hence no fields, you will need a specific path

Re: ListFields returning blanklist

BlakeBarr — Tue, 26 Jul 2016 21:44:42 GMT

The path in the above code is just to protect the privacy of the directory and the data that I am working with. The actual path name leads to a folder with many files including dbf and non dbf. The print table then lists the file inside that directory. Does this help?

Re: ListFields returning blanklist

DanPatterson_Retired — Tue, 26 Jul 2016 21:46:21 GMT

Ok... if the path is correct and the file is a dbase file, and its name prints out, you should be able to get a list of the fields using the syntax in the help... but you say it doesn't work (ps, the field.name, is a string already so no str is needed)

Re: ListFields returning blanklist

DarrenWiens2 — Tue, 26 Jul 2016 21:46:26 GMT

Have you inspected the dBase files within ArcGIS? Possibly a problem in the files themselves?

Re: ListFields returning blanklist

BlakeBarr — Tue, 26 Jul 2016 22:04:17 GMT

I haven't yet. Will look into that now. If I cannot open them in ArcGIS, does that mean I cannot use arcpy tools to convert?

Re: ListFields returning blanklist

DanPatterson_Retired — Tue, 26 Jul 2016 22:21:50 GMT

dbase files can be added to arcmap no problem

Re: ListFields returning blanklist

BlakeBarr — Tue, 26 Jul 2016 22:26:32 GMT

Correct. Removed the string. It seems to be grabbing the file, but does not list the fields.

Re: ListFields returning blanklist

BlakeBarr — Tue, 26 Jul 2016 22:39:27 GMT

Ok, once I get into arcmap, I will get back to you on what it looks like.

Will there be any sign to look for which would tell me why the listfields is not working?

Re: ListFields returning blanklist

DanPatterson_Retired — Sat, 11 Dec 2021 14:26:36 GMT

just write a small script to read it directly from disk in a simple location using listtables, then list fields using the syntax in the link I sent.

import arcpy  # For each field in the Hospitals feature class, print # the field name, type, and length. 
fields = arcpy.ListFields("c:/test/myfile.dbf")  
for field in fields: 
    print("{0} is a type of {1} with a length of {2}" .format(field.name, field.type, field.length))

‍‍‍‍‍

Re: ListFields returning blanklist

BlakeBarr — Sat, 11 Dec 2021 14:26:39 GMT

It's strange. Even when I feed in the direct location of the file, list fields is still returning an empty list?

I made a separate script just to test.

import dbf
import arcpy
import os
import csv

path=r'F:/Datalocation/'
arcpy.env.workspace = path


fields=arcpy.ListFields(r'F:Datalocation//dataset.dbf')
print fields

Returns an empty list.

When I run the exact code you give me. Nothing prints. The listfields list continues to be empty so there is nothing to iterate over. I am not sure why.

Re: ListFields returning blanklist

DanPatterson_Retired — Wed, 27 Jul 2016 11:17:34 GMT

you are mixing filepath syntaxes

r'F:\Datalocation\dataset.dbf'

'F:/Datalocation/dataset.dbf'

Re: ListFields returning blanklist

BlakeBarr — Sat, 11 Dec 2021 14:26:42 GMT

Thanks Dan. Just Fixed that but still having same problem.

import arcpy
import os
import csv

path='F:/Datalocation/'
arcpy.env.workspace = path

fields=arcpy.ListFields('F:/datalocation/dataname.dbf')
for field in fields:  
    print("{0} is a type of {1} with a length of {2}" .format(field.name, field.type, field.length)) 

#This doesn't print. Fields is empty




fieldlist1=[]
tablelist = arcpy.ListTables() # list tables in file
for table in tablelist:
    fieldlist1.append(arcpy.ListFields(table))
print fieldlist1


#This part gives me an "ERROR 999999: ERROR EXECUTING FUNCTION"

Re: ListFields returning blanklist

DanPatterson_Retired — Wed, 27 Jul 2016 11:28:47 GMT

attach the dbf... you may have to zip it to get past upload file types.

Re: ListFields returning blanklist

BlakeBarr — Wed, 27 Jul 2016 11:35:22 GMT

Thanks Dan. Unfortunately, this is confidential data for a research project. I will look more into it but I can't share it. Is there a way to check if the file is corrupted which could be explaining the error?

Re: ListFields returning blanklist

DanPatterson_Retired — Wed, 27 Jul 2016 11:37:34 GMT

open it up in a spreadsheet or some other program

export it out to a csv

if arcmap can load it and you can see the table in arcmap then it should be fine... if not, then it isn't