How can I merge two data sets of different lengths in Python?

Question

I have tried merging with Pandas merge, however, as the length of data is different, merge function is broadcasting the data even when using a key. The following line of code has been used.

dt = pd.merge(df,data[['Post ID','Sentiment']], on = 'Post ID')

Using join produces the following:

df.join(data[['Post ID','Sentiment']],on = 'Post ID')

You are trying to merge on object and int64 columns. If you wish to proceed you should use pd.concat

Possible duplicate of [Trying to merge 2 dataframes but get ValueError](https://stackoverflow.com/questions/50649853/trying-to-merge-2-dataframes-but-get-valueerror) — Rhesous, Jun 28 '18 at 08:13

score 0 · Accepted Answer · edited Jun 26 '18 at 08:36

0

This error means that in one of your database, Post ID is an objectand in the other one it is defined as int. You need to convert them so they have the same type, for instance by doing :

df['Post ID'] = df['Post ID'].astype(int)

edited Jun 26 '18 at 08:36

eyllanesc

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answered Jun 26 '18 at 08:23

Rhesous

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I have tried changing the post ID type to string as Post ID contains both strings and integers. However, the error persists – Parth Batra Jun 26 '18 at 10:30
Could you provide data so we can reproduce your error ? – Rhesous Jun 26 '18 at 10:38
Sorry, I cannot provide the data as it is from a client. – Parth Batra Jun 28 '18 at 07:27

How can I merge two data sets of different lengths in Python?

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