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I was testing a simple connection from an Amazon Redshift database to my local database using PostgreSQL. I wrote a query to obtain a table from the database, and converted that to a pandas DataFrame. Now, whenever I want to apply some functions on the DataFrame objects, I get the following error. I have tried several times to modify it, and looked up a lot of solutions, but can't seem to work around with it.

cur.execute("QUERY for PostgreSQL")
rows = cur.fetchall()
print("Received as rows")
col_names = []
for i in cur.description:
    col_names.append(i[0])
df = pd.DataFrame.from_records(rows, columns = col_names)
df.values()

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-16-8e9714b76ea1> in <module>()
---->  df.values()

TypeError: 'numpy.ndarray' object is not callable
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  • 6
    remove (), need only df.values
    – jezrael
    Commented Sep 20, 2017 at 8:39
  • @jezrael Thanks for the prompt reply! How can I use any other functionalities on my dataframe objects? For example, I want an aggregate of the third column but when I use .mean or .aggregate, it doesn't do that. Also, when I do .describe(), it uses the first column, instead of the third column. How can I approach this?
    – Aman Deep Middha
    Commented Sep 20, 2017 at 8:45
  • I think it is a bit broad, the best is create some data sample and desired output.
    – jezrael
    Commented Sep 20, 2017 at 8:51
  • But I believe docs should help.
    – jezrael
    Commented Sep 20, 2017 at 8:52
  • @jezrael but it doesn't talk about how I can use just one of the columns to get the .describe() to work or mean() over that one column.
    – Aman Deep Middha
    Commented Sep 20, 2017 at 9:01

1 Answer 1

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14

As @jezrael pointed out in the comments, df.values is not a function, so you don't need to call it. Just use df.values instead of df.values().

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  • Thanks! However, if I want to do a .describe() on my third column of the dataframe, how can I do that?
    – Aman Deep Middha
    Commented Sep 20, 2017 at 8:49

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