FAQ: Working with Multiple DataFrames - Review

This community-built FAQ covers the “Review” exercise from the lesson “Working with Multiple DataFrames”.

Paths and Courses
This exercise can be found in the following Codecademy content:

Data Science

Data Analysis with Pandas

FAQs on the exercise Review

Join the Discussion. Help a fellow learner on their journey.

Ask or answer a question about this exercise by clicking reply (reply) below!

Agree with a comment or answer? Like (like) to up-vote the contribution!

Need broader help or resources? Head here.

Looking for motivation to keep learning? Join our wider discussions.

Learn more about how to use this guide.

Found a bug? Report it!

Have a question about your account or billing? Reach out to our customer support team!

None of the above? Find out where to ask other questions here!

Just wondering why the following does not print: “print(v_to_c.time.mean())” ?
Where do I see the answer to the average time? All of the tables print okay.
Also, when I try to just print a string, it does not appear any where.
Is this a limitation to the codeacademy tool?


Having the same problem as bitace81754. The mean time does not print, the exercise says that the code is typed correctly but nothing shows.

Perhaps there should be something inbetween the () in the line "print(v_to_c.time.mean())

What does this parameter do in the pd.read_csv command?


1 Like

You can see the answer in the terminal screen (black one under the script.py screen).

As the answer is not a dataframe, my best guess is that it doesn’t show in the browser screen, but in the terminal screen.

Hope it helps, cheers! :beer:


According the Pandas document of read_csv, it specifies column(s) whose values will be converted to datetime (one of the data types in Python). For example, in the following code:

visits = pd.read_csv('visits.csv', parse_dates=[1])

values of the column visit_time (which has index 1) are converted to datetime.

1 Like

Thank you very much! That’s very useful to know and will be a time saver.

1 Like

What is meant by index 1 of visit_time?

It means visit_time is the second column in the table (note that index starts at 0).

print(visits.columns)  # Index(['user_id', 'visit_time'], dtype='object')

print(visits.columns[0])  # user_id
print(visits.columns[1])  # visit_time

Got it. Thanks. Must be weird coming back to a 2 year old thread haha