question Re: drop a column from csv in Support Questions

drop a column from csv

nishank_paras — Mon, 03 Feb 2020 14:36:26 GMT

how can i drop column from csv

i only want to keep one selected feild

Re: drop a column from csv

cjervis — Mon, 03 Feb 2020 14:11:05 GMT

@nishank_paras Can you provide some additional details for those who may be able to assist you. Specifically, what components (Spark, NiFi, etc.) are you trying to do this with?

Re: drop a column from csv

nishank_paras — Mon, 03 Feb 2020 14:31:34 GMT

i am new to this

i have a csv file with three column name, IP, description

i want to keep ip only and drop other

guide me to the best possible way

listfile ---> fetch file ----> ?? ----->putfile

also tell me the configuration settings if any

Technology - nifi

Re: drop a column from csv

nishank_paras — Mon, 03 Feb 2020 14:30:48 GMT

nifi

Re: drop a column from csv

cjervis — Mon, 03 Feb 2020 14:41:32 GMT

Thank you for the additional information. I have updated the labels for your question so those with an interest in Nifi will be more likely to find it. While you are waiting for someone to answer. Allow me to direct you to something you may not have noticed.

On the right side of this page you should see a list of recommendations.

At the top for me is one that may be of interest with the subject of How to delete a row/drop a column in nifi.

There may be other links of assistance listed as well.

Re: drop a column from csv

nishank_paras — Thu, 06 Feb 2020 09:48:21 GMT

How to delete a row/drop a column in nifi

this is not helping as the configuration are not clear i'm new to this kindly guide if there is any better way

this solution is referencing to the nifi documentation

Re: drop a column from csv

MattWho — Thu, 06 Feb 2020 15:28:43 GMT

@nishank_paras

Without an example input and desired output file, It is difficult to provide an exact solution.
However, you may want to consider using the ReplaceText processor in NiFi.

This processor can be configured with a java regular expression that uses java capture groups to parse your csv file line by line and then use the capture group to replace that lien with only the desired column value.

Just make sure you configure the processor to use "Line-by-Line" instead of the default "Entire text".

Hope this helps you get to a solution that works for you,

Matt

Re: drop a column from csv

nishank_paras — Fri, 07 Feb 2020 09:52:32 GMT

what regex should i use in replace text i have csv in given format

Date, IP, Description

and i want to keep IP only

@MattWho

Re: drop a column from csv

MattWho — Fri, 07 Feb 2020 16:23:10 GMT

@nishank_paras

Let's assume your input FlowFile content looks like this:

Date, IP, Description 01-30-2020, 10.0.0.1, server1 01-30-2020, 10.0.1.2, server2 01-30-2020, 10.0.3.4, server3 01-30-2020, 10.0.4.6, server4 01-30-2020, 10.0.10.2, server5

You would configure your ReplaceText processor as follows:

The Search Value contains a java regular expression which will match on your entire line and uses one capture group. The Replacement Value says to replace everything matched by the Search Value Regex with only the value from capture group 1. We then configure ReplaceText to evaluate that Regex against each line.

The resulting FlowFile output to the success relationship will have content that looks like this:

IP 10.0.0.1 10.0.1.2 10.0.3.4 10.0.4.6 10.0.10.2

Hope this helps,

Matt