The library function random.uniform takes about twice as long as a manual inline implementation (Python 3.9.1).

>>> import timeit
>>> timeit.timeit('3 + (8 - 3) * random.random()', 'import random')
0.1540887290000228
>>> timeit.timeit('a + (b - a) * random.random()', 'import random\na = 3\nb = 8')
0.17950458899986188
>>> timeit.timeit('random.uniform(3, 8)', 'import random')  # does the call/return really add that much overhead?
0.31145418699999894