3b1b-manim/manimlib/utils/iterables.py
2022-03-26 20:52:28 +08:00

139 lines
3.8 KiB
Python

from __future__ import annotations
from typing import Callable, Iterable, Sequence, TypeVar
import numpy as np
T = TypeVar("T")
S = TypeVar("S")
def remove_list_redundancies(l: Iterable[T]) -> list[T]:
"""
Used instead of list(set(l)) to maintain order
Keeps the last occurrence of each element
"""
reversed_result = []
used = set()
for x in reversed(l):
if x not in used:
reversed_result.append(x)
used.add(x)
reversed_result.reverse()
return reversed_result
def list_update(l1: Iterable[T], l2: Iterable[T]) -> list[T]:
"""
Used instead of list(set(l1).update(l2)) to maintain order,
making sure duplicates are removed from l1, not l2.
"""
return [e for e in l1 if e not in l2] + list(l2)
def list_difference_update(l1: Iterable[T], l2: Iterable[T]) -> list[T]:
return [e for e in l1 if e not in l2]
def adjacent_n_tuples(objects: Iterable[T], n: int) -> zip[tuple[T, T]]:
return zip(*[
[*objects[k:], *objects[:k]]
for k in range(n)
])
def adjacent_pairs(objects: Iterable[T]) -> zip[tuple[T, T]]:
return adjacent_n_tuples(objects, 2)
def batch_by_property(
items: Iterable[T],
property_func: Callable[[T], S]
) -> list[tuple[T, S]]:
"""
Takes in a list, and returns a list of tuples, (batch, prop)
such that all items in a batch have the same output when
put into property_func, and such that chaining all these
batches together would give the original list (i.e. order is
preserved)
"""
batch_prop_pairs = []
curr_batch = []
curr_prop = None
for item in items:
prop = property_func(item)
if prop != curr_prop:
# Add current batch
if len(curr_batch) > 0:
batch_prop_pairs.append((curr_batch, curr_prop))
# Redefine curr
curr_prop = prop
curr_batch = [item]
else:
curr_batch.append(item)
if len(curr_batch) > 0:
batch_prop_pairs.append((curr_batch, curr_prop))
return batch_prop_pairs
def listify(obj) -> list:
if isinstance(obj, str):
return [obj]
try:
return list(obj)
except TypeError:
return [obj]
def resize_array(nparray: np.ndarray, length: int) -> np.ndarray:
if len(nparray) == length:
return nparray
return np.resize(nparray, (length, *nparray.shape[1:]))
def resize_preserving_order(nparray: np.ndarray, length: int) -> np.ndarray:
if len(nparray) == 0:
return np.zeros((length, *nparray.shape[1:]))
if len(nparray) == length:
return nparray
indices = np.arange(length) * len(nparray) // length
return nparray[indices]
def resize_with_interpolation(nparray: np.ndarray, length: int) -> np.ndarray:
if len(nparray) == length:
return nparray
if length == 0:
return np.zeros((0, *nparray.shape[1:]))
cont_indices = np.linspace(0, len(nparray) - 1, length)
return np.array([
(1 - a) * nparray[lh] + a * nparray[rh]
for ci in cont_indices
for lh, rh, a in [(int(ci), int(np.ceil(ci)), ci % 1)]
])
def make_even(
iterable_1: Sequence[T],
iterable_2: Sequence[S]
) -> tuple[list[T], list[S]]:
len1 = len(iterable_1)
len2 = len(iterable_2)
if len1 == len2:
return iterable_1, iterable_2
new_len = max(len1, len2)
return (
[iterable_1[(n * len1) // new_len] for n in range(new_len)],
[iterable_2[(n * len2) // new_len] for n in range(new_len)]
)
def hash_obj(obj: object) -> int:
if isinstance(obj, dict):
new_obj = {k: hash_obj(v) for k, v in obj.items()}
return hash(tuple(frozenset(sorted(new_obj.items()))))
if isinstance(obj, (set, tuple, list)):
return hash(tuple(hash_obj(e) for e in obj))
return hash(obj)