Math & Geometry

Integer arithmetic, digits, and coordinate transforms.

Core syntax

• Quotient + remainder — q, r = divmod(a, b).
• Last digit / drop digit — n % 10, n //= 10.
• Rotate a matrix — transpose, then reverse each row.

q, r = divmod(17, 5)          # (3, 2)
matrix[:] = [list(row) for row in zip(*matrix)]   # transpose
for row in matrix:
    row.reverse()

Watch out

• / is float division; use // for integers.