Bringing it all together (1)
This is awesome! You have now learned how to write anonymous functions using lambda, how to pass lambda functions as arguments to other functions such as map(), filter(), and reduce(), as well as how to write errors and output custom error messages within your functions. You will now put together these learnings to good use by working with a Twitter dataset. Before practicing your new error handling skills; in this exercise, you will write a lambda function and use filter() to select retweets, that is, tweets that begin with the string 'RT'.
To help you accomplish this, the Twitter data has been imported into the DataFrame, tweets_df. Go for it!
This exercise is part of the course
Introduction to Functions in Python
Exercise instructions
- In the
filter()call, pass a lambda function and the sequence of tweets as strings,tweets_df['text']. The lambda function should check if the first 2 characters in a tweetxare 'RT'. Assign the resulting filter object toresult. To get the first 2 characters in a tweetx, usex[0:2]. To check equality, use a Boolean filter with==. - Convert
resultto a list and print out the list.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Select retweets from the Twitter DataFrame: result
result = filter(____, ____)
# Create list from filter object result: res_list
____
# Print all retweets in res_list
for tweet in res_list:
print(tweet)