michael 📈 👨💻
@mikedecr.computer
269 followers 295 following 403 posts
Low-latency quant finance R&D. Former political scientist, sometimes bike rider. Long form mikedecr.computer
Low-latency quant finance R&D. Former political scientist, sometimes bike rider. Long form mikedecr.computer
![hy code and output:
(import toolz [first second])
(require hyrule [->])
(defn which [lst]
(-> lst
(enumerate)
((curry filter (compose bool second)))
((curry map first))
(list)))
(which [False False True False True])
[2, 4]](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:qjxju2w5sdit42sjb4qpnatk/bafkreifnww5z4tnt3m7uuoryvws6yil3ezpfcta3bdhojeij455t7lpmoe)
![Screenshot of python code:
@dataclass
class CircuitNetwork:
_circuits: list[Circuit]
# idk if this is the best place for this method but oh well.
def contains_link(self, a: Box, b: Box) -> bool:
"""True if a local circuit contains boxes A and B"""
return any(a in circ and b in circ for circ in self._circuits)
def attach(self, a: Circuit, b: Circuit) -> None:
"""Consolidates circuits A and B into a single circuit"""
assert a != b, "Circuits must be distinct"
assert a in self._circuits, f"Circuit {a=} is not in the network"
assert b in self._circuits, f"Circuit {b=} is not in the network"
self._circuits.remove(a)
self._circuits.remove(b)
self._circuits.append(a.union(b))
def get_circuit(self, pt: Box) -> Circuit:
"""Returns the circuit containing provided Box"""
for circ in self._circuits:
if pt in circ:
return circ](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:qjxju2w5sdit42sjb4qpnatk/bafkreiexx3huyx77qbnnygybqtgwg6jyld2r62q2s5wtc7jcpudhyrxvym)
![def attach_interval(lst: list[Interval], new: Interval) -> list[Interval]:
"""Collapse interval `new` to the last element of `lst` if possible, otherwise append."""
if len(lst) == 0:
lst.append(new)
return lst
if (collapsed := maybe_collapse_intervals(lst[-1], new)):
lst[-1] = collapsed
else:
lst.append(new)
return lst](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:qjxju2w5sdit42sjb4qpnatk/bafkreiatzl2hhgrjj43r6athm237sw5ryivrcbkrhxt7qik4m3w5bnbvaa)
![python code:
def maybe_collapse_intervals(left: Interval, right: Interval) -> tuple[Interval, ...] | None:
"""Return collapsed interval if possible, or None"""
a, b = left
x, y = right
if a <= x <= y <= b: # left contains right
return (a, b)
elif x <= a <= b <= y: # right contains left
return (x, y)
elif a <= x <= b <= y: # left straddles right lower bound
return (a, y)
elif x <= a <= y <= b: # left straddles right upper bound
return (x, b)
else:
return](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:qjxju2w5sdit42sjb4qpnatk/bafkreihew4kkdltzcixghpz32dkyxk2t4dc5xgmqes3ypbrnqifwoa243a)
![Python code:
@app.command()
def day_5_2(test: Flag("--test") = False):
data_path: Path = Data(5, test=test)
intervals_lst: list[Interval] = []
with open(data_path, "r") as f:
for line in f:
if line == "\n":
break
interval: Interval = tuple(eval(chr) for chr in line.strip().split("-"))
intervals_lst.append(interval)
# with the intervals sorted, we can do this w/ reduce
# fn: combine RIGHT w/ tail of LEFT or append RIGHT to LEFT
intervals_lst.sort()
collapsed_intervals: list[Interval] = reduce(attach_interval, intervals_lst, [])
result: int = sum(1 + (right - left) for left, right in collapsed_intervals)
print("solution:", result)
def attach_interval(lst: list[Interval], new: Interval) -> list[Interval]:
"""Collapse interval `new` to the last element of `lst` if possible, otherwise append."""
if len(lst) == 0:
lst.append(new)
return lst
end = lst.pop(-1)
if (collapsed := maybe_collapse_intervals(end, new)):
lst.append(collapsed)
else:
lst.append(end)
lst.append(new)
return lst
def maybe_collapse_intervals(left: Interval, right: Interval) -> tuple[Interval, ...] | None:
"""Return collapsed interval if possible, or None"""
if left[0] <= right[0] <= right[1] <= left[1]: # left contains right
return left
elif right[0] <= left[0] <= left[1] <= right[1]: # right contains left
return right
elif left[0] <= right[0] <= left[1] <= right[1]: # left straddles right lower bound
return (left[0], right[1])
elif right[0] <= left[0] <= right[1] <= left[1]: # left straddles right upper bound
return (right[0], left[1])
else:
return](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:qjxju2w5sdit42sjb4qpnatk/bafkreibhg5rgoaglshy5vitvfu6oaodyodw5jignaikxytstwgbkglntbe)
![screenshot of a terminal command and output:
uv run tmd parse --archive ../twitter-archive/twits -o tweets.json && head -20 tweets.json
[
{
"tweet": {
"edit_info": {
"initial": {
"editTweetIds": [
"1855701514406309953"
],
"editableUntil": "2024-11-10T20:58:12.000Z",
"editsRemaining": "5",
"isEditEligible": true
}
},
"retweeted": false,
"source": "<a href=\"https://mobile.twitter.com\" rel=\"nofollow\">Twitter Web App</a>",
"entities": {
"hashtags": [],
"symbols": [],
"user_mentions": [],
"urls": []](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:qjxju2w5sdit42sjb4qpnatk/bafkreidu2by5arikedxqg4jyqa2yfgeup2yozzmcmjiytybbkok3h72jfy)
!["""
No-Significant-Whitespace Python.
Not even function defs!
"""
import itertools
from pathlib import Path
from typing import Any, List, Callable as Function
parse_words: Function[str, List[str]] = lambda chars: \
[s for s in chars.split(" ") if s != ""]
parse_int_sequence: Function[str, List[int]] = lambda chars: \
[int(word) for word in parse_words(chars)]
diff_series: Function[List[int], List[int]] = lambda series: \
[a - b for a, b in itertools.pairwise(series)]
all_same_sign: Function[List[int], bool] = lambda seq: \
all(x < 0 for x in seq) or all(x > 0 for x in seq)
# haters weep that we find a use for this yet again...
juxt: Function[List[Function], Function[Any, List[Any]]] = lambda fns: \
lambda *args, **kws: [fn(*args, **kws) for fn in fns]
good_seq_checks: Function[List[int], List[bool]] = lambda seq: \
juxt([all_same_sign, lambda lst: all(1 <= abs(x) <= 3 for x in lst)])(diff_series(seq))
is_safe_sequence: Function[List[int], bool] = lambda seq: \
all(good_seq_checks(seq))
part_one: Function[Path, int] = lambda filepath: \
sum(is_safe_sequence(parse_int_sequence(seq))
for seq in open(filepath).read().splitlines())
if __name__ == "__main__":
pt2_data = Path("data/2024/02")
test_file = pt2_data / "test.txt"
final_file = pt2_data / "final.txt"
assert part_one(test_file) == 2
print(f"{part_one(final_file)=}")](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:qjxju2w5sdit42sjb4qpnatk/bafkreiazkdesegphdbdhkwjp72vxbvsymopoqtg4hef3e5uxexkauipldy)
![Rendered web page, dark screen, monospace text, orange accent color, very retro terminal looking.
Text is rendered latex from following code:
Dollars $ a = x $ and parens \(b + c\)
Double dollar:
$$
a = x
$$
Square bracket:
\[
a + 1
\]
Escaping dollars between \\$100 and \\$200.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:qjxju2w5sdit42sjb4qpnatk/bafkreid4tcbotqh5m5w3vqw6r4aoma7wofgpnfanqxifzqubtcltoavdpe)
![Python code:
import polars as pl
class Columns:
def __getattr__(self, name) -> pl.Expr:
if name.startswith("_"):
raise AttributeError(name)
return pl.col(name)
def __getitem__(self, name) -> pl.Expr:
return pl.col(name)
c = Columns()
df = pl.DataFrame({"foo": [1, 2, 3], "bar": [4, 5, 6]})
df.with_columns(baz=c.foo + c.bar)
# shape: (3, 3)
# ┌─────┬─────┬─────┐
# │ foo ┆ bar ┆ baz │
# │ --- ┆ --- ┆ --- │
# │ i64 ┆ i64 ┆ i64 │
# ╞═════╪═════╪═════╡
# │ 1 ┆ 4 ┆ 5 │
# │ 2 ┆ 5 ┆ 7 │
# │ 3 ┆ 6 ┆ 9 │
# └─────┴─────┴─────┘](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:qjxju2w5sdit42sjb4qpnatk/bafkreiceozkeqxmhzvxd7ljkmv35t3zns43nbpk26xcox3llbmaxcx2wam)
![screenshot of python code:
# this is the classical definition of map
def map(fn, xs: list):
if len(xs) == 0:
return []
else:
return [fn(xs[0]), *map(fn, xs[1:])]
# but you can implement as a reduce
from functools import reduce
def map(fn, xs: list):
return reduce(_as_binary_op(fn), xs, list())
# casting func into a binary operation
def _as_binary_op(fn):
def binary_op(accum: list, x):
accum.append(fn(x))
return accum
return binary_op
map(str.upper, ["a", "b", "c"])
# ['A', 'B', 'C']](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:qjxju2w5sdit42sjb4qpnatk/bafkreib3uewhacxopg5lq2yyxbbzb6ak54naobefs4c42bnrthfsb4t32e)
![R REPL input and output:
[r] ▶ devtools::load_all()
ℹ Loading prefix
[r] ▶ mult(2, 5)
[1] 10
[r] ▶ mult(2)
function(...) operator(a, ...)
<environment: 0x11ff4d000>
[r] ▶ dbl = mult(2)
[r] ▶ dbl(5)
[1] 10](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:qjxju2w5sdit42sjb4qpnatk/bafkreidymimnnm7tqfu5iplcqvug6nasbdndgecc6nxuta5jcotcwa734m)