# tag::COLUMNIZE[]

from typing import Sequence, Tuple, Iterator

def columnize(sequence: Sequence[str], num_columns: int = 0) -> Iterator[Tuple[str, ...]]:

if num_columns == 0:

num_columns = round(len(sequence) ** .5)

num_rows, reminder = divmod(len(sequence), num_columns)

num_rows += bool(reminder)

return (tuple(sequence[i::num_rows]) for i in range(num_rows))

# end::COLUMNIZE[]

def demo() -> None:

nato = ('Alfa Bravo Charlie Delta Echo Foxtrot Golf Hotel India'

' Juliett Kilo Lima Mike November Oscar Papa Quebec Romeo'

' Sierra Tango Uniform Victor Whiskey X-ray Yankee Zulu'

).split()

for row in columnize(nato, 4):

for word in row:

print(f'{word:15}', end='')

print()

if __name__ == '__main__':

demo()