Generate diff of two CSV files based on a single column using Pandas - pandas

Question

I am working with CSV files that are each hundreds of megabytes (800k+ rows), use pipe delimiters, and have 90 columns. What I need to do is compare two files at a time, generating a CSV file of any differences (i.e. rows in File2 that do not exist in File1 as well as rows in File1 that do not exist in File2) but performing the comparison Only using a single column.
For instance, a highly simplified version would be:
File1
claim_date|status|first_name|last_name|phone|claim_number
20200501|active|John|Doe|5555551212|ABC123
20200505|active|Jane|Doe|5555551212|ABC321
File2
claim_date|status|first_name|last_name|phone|claim_number
20200501|active|Someone|New|5555551212|ABC123
20200510|active|Another|Person|5555551212|ABC000
In this example, the output file should look like this:
claim_date|status|first_name|last_name|phone|claim_number
20200505|active|Jane|Doe|5555551212|ABC321
20200510|active|Another|Person|5555551212|ABC000
As this example shows, both input files contained the row with claim_number ABC123 and although the fields first_name and last_name changed between the files I do not care as the claim_number was the same in both files. The other rows contained unique claim_number values and so both were included in the output file.
I have been told that Pandas is the way to do this, so I have set up a Jupyter environment and am able to load the files correctly but am banging my head against the wall at this point. Any suggestions are Highly appreciated!
My code so far:
import os
import pandas as pd
df1 = pd.read_table("/Users/X/Claims_20210607.txt", sep='|', low_memory=False)
df2 = pd.read_table("/Users/X/Claims_20210618.txt", sep='|', low_memory=False)
Everything else I've written is basically irrelevant at this point as it's just copypasta from the web that doesn't execute for one reason or another.
EDIT: Solution!
import os
import pandas as pd
df1 = pd.read_table("Claims_20210607.txt", sep='|', low_memory=False)
df2 = pd.read_table("Claims_20210618.txt", sep='|', low_memory=False)
df1.astype({'claim_number':'str'})
df2.astype({'claim_number':'str'})
df = pd.concat([df1,df2])
(
df.drop_duplicates(
subset=['claim_number'],
keep = False,
ignore_index=True)
.to_csv('diff.csv')
)
I still need to figure out how to kill off the first / added column before writing the file but this is fantastic! Thanks!

Answer 1

IIUC, you can try:
If you wanna drop duplicates based on all columns except ['first_name', 'last_name']:
df = pd.concat([df1, df2])
(
df.drop_duplicates(
subset=df.columns.difference(['first_name', 'last_name']),
keep=False)
.to_csv('file3.csv')
)
If you wanna drop duplicates based on duplicate claim_number column only:
df = pd.concat([df1,df2])
(
df.drop_duplicates(
subset=['claim_number'],
keep = False)
.to_csv('file3.csv')
)