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  3. Python Data Science Toolbox (Part 2)

Exercise

Conditional list comprehensions for time-stamped data

Great, you've successfully extracted the data of interest, the time, from a pandas DataFrame! Let's tweak your work further by adding a conditional that further specifies which entries to select.

In this exercise, you will be using a list comprehension to extract the time from time-stamped Twitter data. You will add a conditional expression to the list comprehension so that you only select the times in which entry[17:19] is equal to '19'. The pandas package has been imported as pd and the file 'tweets.csv' has been imported as the df DataFrame for your use.

Instructions

100 XP
  • Extract the column 'created_at' from df and assign the result to tweet_time.
  • Create a list comprehension that extracts the time from each row in tweet_time. Each row is a string that represents a timestamp, and you will access the 12th to 19th characters in the string to extract the time. Use entry as the iterator variable and assign the result to tweet_clock_time. Additionally, add a conditional expression that checks whether entry[17:19] is equal to '19'.