From 3cf9f9452b007fa26701346fd39c155fd97dbb27 Mon Sep 17 00:00:00 2001
From: Alan Orth <alan.orth@gmail.com>
Date: Sat, 27 Jul 2019 01:28:08 +0300
Subject: [PATCH] csv_metadata_quality/check.py: Always return field

We always need to return the field back so apply doesn't set it to
null when creating the new data frame.
---
 csv_metadata_quality/check.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/csv_metadata_quality/check.py b/csv_metadata_quality/check.py
index 0568a50..559d7e6 100755
--- a/csv_metadata_quality/check.py
+++ b/csv_metadata_quality/check.py
@@ -22,6 +22,8 @@ def issn(field):
         if not issn.is_valid(value):
             print(f'Invalid ISSN: {value}')
 
+    return field
+
 
 def isbn(field):
     """Check if an ISBN is valid.
@@ -45,6 +47,8 @@ def isbn(field):
         if not isbn.is_valid(value):
             print(f'Invalid ISBN: {value}')
 
+    return field
+
 
 def separators(field):
     """Check for invalid multi-value separators (ie "|" or "|||").
@@ -66,3 +70,6 @@ def separators(field):
 
         if len(match) > 0:
             print(f'Invalid multi-value separator: {field}')
+
+
+    return field