Measuring time II
As we discussed in the lectures, in the majority of cases, a list comprehension is faster than a for loop.
In this demonstration, you will see a case where a list comprehension and a for loop have so small difference in efficiency that choosing either method will perform this simple task instantly.
In the list words
, there are random words downloaded from the Internet. We are interested to create another list called listlet
in which we only keep the words that start with the letter b
.
In case you are not familiar with dealing with strings in Python, each string has the .startswith()
attribute, which returns a True/False statement whether the string starts with a specific letter/phrase or not.
This exercise is part of the course
Writing Efficient Code with pandas
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Store the time before the execution
start_time = time.___()
# Execute the operation
letlist = [wrd for wrd in words if wrd.startswith('b')]
# Store and print the difference between the start and the current time
total_time_lc = time.time() - ___
print('Time using list comprehension: {} sec'.format(total_time_lc))