During the Neo4j How I met your mother hackathon that we ran last week one of the attendees noticed that one of the CSV files we were importing wasn’t creating as many records as they expected it to.

This is typically the case when there’s some odd quoting in the CSV file but we decided to look into it.

The file in question was one containing references made in HIMYM. The first 5 lines look like this: _~bash $ head -n 5 data/import/references.csv ReferencedEpisodeId,ReferencingEpisodeId,ReferenceText 168,184,"Marshall will eventually hear back from the New York State Judicatory Committee in Something New, which will become a main plot point of Season 9." 168,169,Barney proclaiming to be done with Robin will be the focal point of Lobster Crawl. 58,57,"Barney finally confronts his saboteur (Abby, whom he slept with in Ten Sessions) in Everything Must Go." 58,63,"Barney finally confronts his saboteur (Abby, whom he slept with in Ten Sessions) in Everything Must Go." _~

And this is how many lines the Unix 'wc' command sees: _~bash $ wc -l data/import/references.csv 782 data/import/references.csv _~

So we might expect that there are going to be 782 records created if we import that file into Neo4j. Let’s run a quick query in Neo4j to see what it thinks: _~cypher LOAD CSV WITH HEADERS FROM "file:///Users/markneedham/projects/neo4j-himym/data/import/references.csv" AS row return count() ==> ---------- ==> | count() | ==> ---------- ==> | 636 | ==> ---------- ==> 1 row _~

So we have 146 less records than we expected which means Neo4j is treating multiple lines as one CSV line in some cases.

Let’s go back to the Unix command line to try and work out which lines those are. There must be some lines which start with part of the 'ReferenceText' rather than a 'ReferenceEpisodeId' so let’s extract the first column and see what’s going on there: _~bash $ cat data/import/references.csv | cut -d"," -f1 | grep -v '[0-9]\+$'| head -n 10 ReferencedEpisodeId This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny Also _~

We’ve extracted the first column and then filter the output to only keep rows which don’t contain all numbers which will be our rogue rows.

Let’s switch back to Neo4j land to see which rows it thinks contains these fragments of text: _~cypher LOAD CSV WITH HEADERS FROM "file:///Users/markneedham/projects/neo4j-himym/data/import/references.csv" AS row WITH row WHERE row.ReferenceText =~ ".This is the Mother’s first." RETURN row.ReferencedEpisodeId, row.ReferencingEpisodeId, row.ReferenceText ==> -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ==> | row.ReferencedEpisodeId | row.ReferencingEpisodeId | row.ReferenceText | ==> -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ==> | "45" | "37" | "This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> | "45" | "184" | "This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- _~

Interestingly it only returns two rows containing that phrase whereas we see it at least 8 times. Initially I thought this was an issue with the LOAD CSV command but if we filter the rows to only return ones that have a 'ReferencedEpisodeId' of '45' then we do see them returned: _~cypher ==> --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ==> | row | ==> --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "53", ReferenceText -> "The website counting down to the next slap (slapcountdown.com) that Marshall sends Barney reaches zero in Slapsgiving, when the third slap is delivered."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "55", ReferenceText -> "Ted gets rid of his butterfly tramp stamp through ten weekly sessions of laser tattoo removal between The Platinum Rule and Ten Sessions, over the course of which he meets, asks out, and eventually starts dating his dermatologist, Stella Zinman."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "57", ReferenceText -> "Ted gets rid of his butterfly tramp stamp through ten weekly sessions of laser tattoo removal between The Platinum Rule and Ten Sessions, over the course of which he meets, asks out, and eventually starts dating his dermatologist, Stella Zinman."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "56", ReferenceText -> "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. ==> This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "200", ReferenceText -> "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. ==> This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "100", ReferenceText -> "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. ==> This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "86", ReferenceText -> "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. ==> This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "113", ReferenceText -> "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. ==> This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "161", ReferenceText -> "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. ==> This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "37", ReferenceText -> "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. ==> This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "184", ReferenceText -> "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. ==> This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "37", ReferenceText -> "This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "184", ReferenceText -> "This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "63", ReferenceText -> "Marshall makes other home-made websites in Everything Must Go (lilyandmarshallselltheirstuff.com) and The Sexless Innkeeper (itwasthebestnightever.com), where Lily and Future Ted mention it being a problem."} | ==> | {ReferencedEpisodeId -> "45", ReferencingEpisodeId -> "92", ReferenceText -> "Marshall makes other home-made websites in Everything Must Go (lilyandmarshallselltheirstuff.com) and The Sexless Innkeeper (itwasthebestnightever.com), where Lily and Future Ted mention it being a problem."} | ==> --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- _~

So the actual problem is that the regex matcher doesn’t deal with the new line in the string.

Our next step is therefore to get rid of new lines within strings. I spent ages trying to find the appropriate command before coming across the following use of awk which does the job: _~bash $ cat data/import/references.csv | awk '(NR-1)%2{$1=$1} {print $0}' RS=\" ORS=\" | wc -l 637 $ cat data/import/references.csv | awk '(NR-1)%2{$1=$1} {print $0}' RS=\" ORS=\" > data/import/refs.csv _~

Let’s try the LOAD CSV command again: _~cypher LOAD CSV WITH HEADERS FROM "file:///Users/markneedham/projects/neo4j-himym/data/import/refs.csv" AS row WITH row WHERE row.ReferenceText =~ ".This is the Mother’s first." RETURN row.ReferencedEpisodeId, row.ReferencingEpisodeId, row.ReferenceText ==> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ==> | row.ReferencedEpisodeId | row.ReferencingEpisodeId | row.ReferenceText | ==> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ==> | "45" | "56" | "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> | "45" | "200" | "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> | "45" | "100" | "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> | "45" | "86" | "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> | "45" | "113" | "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> | "45" | "161" | "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> | "45" | "37" | "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> | "45" | "184" | "Ted eventually acquires the yellow umbrella in No Tomorrow (after the Mother leaves it behind at the St. Patrick’s Day party, as seen in How Your Mother Met Me), and leaves it in Cindy’s and the Mother’s apartment in Girls Versus Suits. The umbrella is also seen/referenced in many other episodes, including Right Place, Right Time, Big Days, and Farhampton. This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> | "45" | "37" | "This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> | "45" | "184" | "This is the Mother’s first on-screen appearance with the yellow umbrella. Previously she appeared in Lucky Penny, with her head obscured by a bridal veil. She is seen again in No Tomorrow, again hidden by the umbrella, her ankle is seen briefly in Girls Versus Suits, and she gets her first proper appearance in Something New, after which she appears throughout Season 9." | ==> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- _~

And there we go!