The random module generates pseudo-random values and makes selections from collections. Its results depend on an internal state, so a seed can make behavior reproducible for tests and demonstrations. section 9.1.2 section 9.3.4
Common operations include:
- Call random.choice() to select one item from a list and random.sample() to select several items. section 9.5
- Call random.seed(value) with a hashable value, commonly an integer, to reproduce a sequence of pseudo-random decisions. section 9.3.4
- Call random.shuffle(list) to reorder a mutable list in place; the method returns None. section 16.1.4
Reproducible random output
A command-line program can pass an integer seed to random.seed(args.seed), then select words to generate predictable output during tests. Without a supplied seed, random.seed(None) behaves like leaving the generator unseeded. section 9.1.2 section 12.0
Scrambling mutable data
To scramble the middle of a word, convert the string slice to a list, shuffle that list, and join it with the unchanged first and last characters. Strings cannot be shuffled in place. section 16.1.4
random.seed(args.seed)
Inspect the minimal seeding call used to control pseudo-random behavior. section 9.3.4
