numpy.ndarray' object is not callable - Using Pandas

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