random

random defines functions that generate random values for various distributions, it's intended to be a drop-in subset of Python's random module for Starlark.

Functions

`randbytes(n)`

Generate a random byte string containing n number of bytes.

Parameters

name	type	description
`n`	`int`	If n bytes is non-positive or not supplied, a reasonable default is used.

Examples

basic

Generate a random byte string containing 10 bytes.

load("random", "randbytes")
b = randbytes(10)
print(b)
# Output: b'K\xaa\xbb4\xbaEh0\x19\x9c'

`randstr(chars, n)`

Generate a random string containing n number of unicode characters from the given unicode string.

Parameters

name	type	description
`chars`	`string`	The characters to choose from.
`n`	`int`	The length of the string. If n is non-positive or not supplied, a reasonable default is used.

Examples

basic

Generate a random string containing 10 characters from the given unicode string.

load("random", "randstr")
s = randstr("abcdefghijklmnopqrstuvwxyz", 10)
print(s)
# Output: "enfknqfbra"

`randb32(n, sep)`

Generate a random base32 string containing n number of bytes with optional separator dash for every sep characters.

Parameters

name	type	description
`n`	`int`	The number of bytes to generate. If n is non-positive or not supplied, a reasonable default is used.
`sep`	`int`	The number of characters to separate with a dash, if it's non-positive or not supplied, no separator is used.

Examples

basic

Generate a random base32 string containing 10 bytes with no separator.

load("random", "randb32")
s = randb32(10, 4)
print(s)
# Output: 2RXQ-H45H-WV

`randint(a,b)`

Return a random integer N such that a <= N <= b.

Parameters

name	type	description
`a`	`int`	The lower bound of the range.
`b`	`int`	The upper bound of the range.

Examples

basic

Return a random integer N such that 0 <= N <= 10.

load("random", "randint")
n = randint(0, 10)
print(n)
# Output: 7

`random()`

Return a random floating point number in the range 0.0 <= X < 1.0.

Examples

basic

Return a random floating point number in the range [0.0, 1.0).

load("random", "random")
n = random()
print(n)
# Output: 0.7309677873766576

`uniform(a, b)`

Return a random floating point number N such that a <= N <= b for a <= b and b <= N <= a for b < a. The end-point value b may or may not be included in the range depending on floating-point rounding in the equation a + (b-a) * random().

Parameters

name	type	description
`a`	`float`	The lower bound of the range.
`b`	`float`	The upper bound of the range.

Examples

basic

Return a random floating point number N such that 5.0 <= N <= 10.0.

load("random", "uniform")
n = uniform(5, 10)
print(n)
# Output: 7.309677873766576

`uuid()`

Generate a random UUID (RFC 4122 version 4).

Examples

basic

Generate a random UUID.

load("random", "uuid")
u = uuid()
print(u)
# Output: 6e360b7a-f677-4f6c-9c57-8b09694d66b3

`choice(seq)`

Return a random element from the non-empty sequence seq.

Parameters

name	type	description
`seq`	`list`	A non-empty sequence.

Examples

basic

Return a random element from the non-empty sequence [1, 2, 3, 4, 5].

load("random", "choice")
n = choice([1, 2, 3, 4, 5])
print(n)
# Output: 3

`shuffle(x)`

Shuffle the sequence x in place.

Parameters

name	type	description
`x`	`list`	A non-empty sequence.

Examples

basic

Shuffle the sequence [1, 2, 3, 4, 5] in place.

load("random", "shuffle")
x = [1, 2, 3, 4, 5]
shuffle(x)
print(x)
# Output: [3, 1, 5, 4, 2]

Last modified: 18 May 2024