Data Science Tool Box - 2

Question 1

What is an iterable and an iterator?

Answer 1

An iterable is an object that can return an iterator, while an iterator is an object that keeps state and produces the next value when you call next() on it.

Question 2

What does the enumerate () do?

Answer 2

enumerate() returns an enumerate object that produces a sequence of tuples, and each of the tuples is an index-value pair.

Question 3

z1 = zip(mutants,powers)

result1, result2 = zip(*z1)

Answer 3

This code zips and then unzips the lists back to their original list form (result1, result2 = zip(*z1))

Question 4

What does the argument chunksize in the read_csv() do?

Answer 4

Sometimes, the data we have to process reaches a size that is too much for a computer’s memory to handle. This is a common problem faced by data scientists. A solution to this is to process an entire data source chunk by chunk, instead of a single go all at once.

Question 5

The following list has been pre-loaded in the environment.

doctor = [‘house’, ‘cuddy’, ‘chase’, ‘thirteen’, ‘wilson’]

How would a list comprehension that produces a list of the first character of each string in doctor look like?

Answer 5

The list comprehension is [doc[0] for doc in doctor] and produces the list [‘h’, ‘c’, ‘c’, ‘t’, ‘w’].