6.4 Nested Loops

3 practice questionsNot yet reviewed

Notes

A nested loop is a loop inside another loop. The inner loop runs completely for each repetition of the outer loop.

for row in range(2):
for col in range(3):
print("*", end="")
print()

Output: *** on one line, then *** on a second line.
end="" stops print from starting a new line, and print() alone moves to the next line.
Total repetitions of the inner body = outer count x inner count. Here 2 x 3 = 6 stars.
Nested loops are used for grids, tables and comparing every pair of items.

A nested loop has an outer for that runs 4 times and an inner for that runs 5 times. How many times does the inner body run in total?

What does the nested loop above print if the outer range is range(3) and the inner range is range(2)?

In a nested loop, when does the inner loop restart?