This community-built FAQ covers the “Review” exercise from the lesson “Working with Multiple DataFrames”.
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This exercise can be found in the following Codecademy content:
Data Science
Data Analysis with Pandas
FAQs on the exercise Review
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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?
2 Likes
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?
parse_dates=[1]
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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! 
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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.
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Thank you very much! That’s very useful to know and will be a time saver.
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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
