Find Dataframe field in another frame and flag it if found

Question

I have two data frame wants to compare some fields between two and if filed found in both the data frame then flag it to true else false. here StoreId And PartyCode is a composite key.

Code:

df1 = DataFrame({'StoreId': [1, 2, 3], 'PartyCode': ['a', 'b', 'c'],'anotherfiled': ['x', 'y', 'z']})
df2 = DataFrame({'StoreId': [1, 5,4], 'PartyCode': ['a', 'b','d']})
df1.isin(df2)

Expected Output:

@jezrael why did you reopen with no comment or discussion? This is obviously a duplicate and adding `.astype(int)` is not a reason to reopen — cs95, Jan 27 '20 at 08:29
@cs95 - hmmm, because part time dupe, please find better match and I close answer. — jezrael, Jan 27 '20 at 08:31
@jezrael how about [(1)](https://stackoverflow.com/q/47498769/), [(2)](https://stackoverflow.com/q/55790602/), [(3)](https://stackoverflow.com/a/54842060) all by you... woooow... this was from page 1 if you need more duplicates I can help you find them — cs95, Jan 27 '20 at 08:34
@jezrael, i have to compare tow fields StoreId and PartyCode Combination like composite key — Juned Ansari, Jan 27 '20 at 09:36
Can you create [minimal, complete, and verifiable example](http://stackoverflow.com/help/mcve) ? — jezrael, Jan 27 '20 at 09:39
@jezrael, you marked as a duplicate but non of above solutions resolves my problem. its related to multiple fields comparision — Juned Ansari, Jan 27 '20 at 09:44
@JunedAnsari - Can you change data for mcve? Because now solution bellow working perfectly with sample data. — jezrael, Jan 27 '20 at 09:45
@jezrael, now check updated question, below solution will not work, i have changes storeid from 2 to 5 in df2 — Juned Ansari, Jan 27 '20 at 09:50
@JunedAnsari - match is by `PartyCode`, so still working nice — jezrael, Jan 27 '20 at 09:51
@jezrael just in case you're unaware: you can edit the duplicate target list without reopening and reclosing the question. — Andras Deak -- Слава Україні, Jan 27 '20 at 10:21
@AndrasDeak - I reopened first dupe, so I closed, because I think dupe. Unfortunately now I cannot reopen — jezrael, Jan 27 '20 at 10:22
@jezrael I saw that you closed it again which is why I left the comment. Why would you want to reopen again? — Andras Deak -- Слава Україні, Jan 27 '20 at 10:29
@AndrasDeak - Because OP reported not dupe. What is correct way? Reopen? — jezrael, Jan 27 '20 at 10:32
We can tell @cs95 that OP thinks the dupes are insufficient so he should look for new ones. — Andras Deak -- Слава Україні, Jan 27 '20 at 10:33

score 2 · Accepted Answer · answered Jan 27 '20 at 08:12

2

You have to specify the column you want to check.

df1.loc[:, "flag"] = df1['PartyCode'].isin(df2['PartyCode'])
df1

So your output is the same as you requested.

    StoreId PartyCode   anotherfiled    flag
0     1       a            x            True
1     2       b            y            True
2     3       c            z            False

answered Jan 27 '20 at 08:12

sergiomahi

964
2
8
21

And from here the very trivial fix to get the expected output is `df1['PartyCode'].isin(df2['PartyCode']).astype(int)` – cs95 Jan 27 '20 at 08:27
what about StoreId? because StoreId and PartyCode is composite key – Juned Ansari Jan 27 '20 at 09:05

Find Dataframe field in another frame and flag it if found

1 Answers1