CSV python module print none from a csv file

Question

I want to read data from a CSV file but my output says field values in the rows are "None". It doesn't recognize the values in my CSV file.

Any ideas ?

Here's the code I am using :

import arcpy
import csv
arcpy.env.workspace = "D:"
csvfile             = "D:/file.csv"
domains = []
rows = []

with open(csvfile, 'r') as csvfile:
     reader = csv.DictReader(csvfile)
     for row in reader:
     try:
        domains.append(row.get('domain'))
        rows.append(row)
    except KeyError:
       rows = [row]

domains = list(set(domains))
print("Identified %s unique domains" % len(domains))
print("Identified %s codes" % len(rows))


print("Creating codes:")
for row in rows:
    print("%s\t%s\t%s" % (row.get('domain'), row.get('code'), row.get('code_description')))

Here's a sample of my csv file, very basic and tab delimitated.

And here's the result i am getting :

Here's the print of the rows:

Please fix the indentation. Also, you may want to transform domains into a set from the start instead of appending to a list. — Adirio
– Adirio, Commented Sep 29, 2020 at 7:52
some_dict.get('some_key') will never raise a KeyError, it will return None if it can't find it. try swapping it to domains.append(row['domain']). — Adirio
– Adirio, Commented Sep 29, 2020 at 7:56

Adirio · Accepted Answer · 2020-09-29 08:37:46Z

1

Aside from the indentaiton issues, try the following modification:

import arcpy
import csv
arcpy.env.workspace = "D:"
csvfile             = "D:/file.csv"
domains = set()
rows = []

with open(csvfile, 'r') as csvfile:
    reader = csv.DictReader(csvfile, delimiter=';')
    for row in reader:
        try:
            domains.add(row['domain'])
            rows.append(row)
        except KeyError:
            print("Couldn't parse", row)

print("Identified %s unique domains" % len(domains))
print("Identified %s codes" % len(rows))


print("Creating codes:")
for row in rows:
    print("%s\t%s\t%s" % (row.get('domain'), row.get('code'), row.get('code_description')))

edited Sep 29, 2020 at 8:37

answered Sep 29, 2020 at 7:59

Adirio

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10 Comments

Mar Over a year ago

Thank you but there is a syntax error somewhere in your code

Adirio Over a year ago

@Mar python version?

Mar Over a year ago

it's a python27

Adirio Over a year ago

Python 2.7 reached end of support by january 2020, you should definetely update to python 3. I edited it to remove the python 3.6 addition (we are in 3.8 stable right now), f-strings.

Mar Over a year ago

yes you are right i should update to python 3 eventually. hence your updates are not working, now my csv reactes as it's empty , no results at all !

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