slice_states

Retain a contiguous slice of a pool’s state space using standard Python slice syntax, without altering the sequences themselves.

import poolparty as pp
pp.init()

Parameters

Parameter	Type	Default	Description
`pool`	`Pool`	(required)	Input pool whose state space will be sliced.
`key`	`int \| slice`	(required)	Integer index (single state) or `slice` object specifying which states to retain. Supports negative indices and standard Python slice syntax.
`prefix`	`str \| None`	`None`	Prefix for the operation node name in the pool graph.
`iter_order`	`float \| None`	`None`	Enumeration order when combined with other pools.

Note

Only the most commonly used parameters are shown above. For the full parameter list, see state_slice() in the API Reference.

Take the first eight states of the 16-state 2-mer enumeration to obtain the eight 2-mers that begin with A or C.

kmers  = pp.get_kmers(length=2, mode="sequential")
first8 = pp.state_slice(kmers, slice(0, 8))
first8.print_library()

first8: seq_length=2, num_states=8 AA
AC
AG
AT
CA
CC
CG
CT

Select a window in the middle of the state space to focus on a particular sub-range of sequences without regenerating the entire pool.

kmers = pp.get_kmers(length=2, mode="sequential")
mid   = pp.state_slice(kmers, slice(10, 15))
mid.print_library()

mid: seq_length=2, num_states=5 GG
GT
TA
TC
TG

Negative indices count from the end of the state space, mirroring Python list slicing conventions.

kmers = pp.get_kmers(length=2, mode="sequential")
last4 = pp.state_slice(kmers, slice(-4, None))
last4.print_library()

last4: seq_length=2, num_states=4 TA
TC
TG
TT