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Python Programming - Generators

Exercise : Generators - General Questions
  • Generators - General Questions
61.
How does the generator.throw(StopIteration) method affect a running generator?
It stops the generator and raises a StopIteration exception
It continues the generator's execution
It restarts the generator from the beginning
It has no effect on the running generator
Answer: Option
Explanation:
generator.throw(StopIteration) stops the generator and raises a StopIteration exception. However, using raise StopIteration directly is preferred. 
def my_generator():
    try:
        while True:
            yield 1
    except StopIteration:
        print("Generator stopped")

gen = my_generator()
next(gen)
gen.throw(StopIteration)
62.
What happens if the generator.throw(ValueError, "message") method is called with a non-existent exception type?
It raises a TypeError
It raises the specified exception with the provided message
It has no effect on the running generator
It raises a GeneratorExit exception
Answer: Option
Explanation:
If the specified exception type does not exist, generator.throw() has no effect on the running generator.
63.
What is the purpose of the itertools.groupby() function when used with generators?
It groups consecutive equal elements from the generator
It interleaves values from different generators
It stops the generator after one iteration
It creates pairs of values from the generators
Answer: Option
Explanation:
itertools.groupby() groups consecutive equal elements from the generator based on a key function. 
import itertools

def my_generator():
    yield 1
    yield 1
    yield 2
    yield 3
    yield 3

grouped_generator = itertools.groupby(my_generator())

for key, group in grouped_generator:
    print(f"Key: {key}, Group: {list(group)}")
64.
How does the itertools.zip_longest() function differ from zip() when used with generators?
They are equivalent in functionality
itertools.zip_longest() fills in missing values with None, while zip() stops when the shortest iterable is exhausted
zip() fills in missing values with None, while itertools.zip_longest() stops when the shortest iterable is exhausted
itertools.zip_longest() raises a ValueError if iterables are of different lengths
Answer: Option
Explanation:
itertools.zip_longest() fills in missing values with None for the shorter iterables, while zip() stops when the shortest iterable is exhausted. 
import itertools

gen1 = (1, 2, 3)
gen2 = ('a', 'b')

zipped = zip(gen1, gen2)
zip_longest = itertools.zip_longest(gen1, gen2)

print(list(zipped))       # Output: [(1, 'a'), (2, 'b')]
print(list(zip_longest))  # Output: [(1, 'a'), (2, 'b'), (3, None)]
65.
How does the itertools.filterfalse() function differ from filter() when used with generators?
They are equivalent in functionality
itertools.filterfalse() filters elements based on a false condition, while filter() filters based on a true condition
filter() filters elements based on a false condition, while itertools.filterfalse() filters based on a true condition
itertools.filterfalse() raises a ValueError if the filtering function is not provided
Answer: Option
Explanation:
itertools.filterfalse() filters elements from the generator for which the filtering function returns false, while filter() filters based on a true condition.
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