(by @andrestaltz)
If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.
// Sample custom iterator. | |
// By perfectly.insane (http://www.dreamincode.net/forums/index.php?showuser=76558) | |
// From: http://www.dreamincode.net/forums/index.php?showtopic=58468 | |
#include <iostream> | |
#include <vector> | |
#include <algorithm> | |
#include <iterator> | |
#include <cassert> |
-- show running queries (pre 9.2) | |
SELECT procpid, age(clock_timestamp(), query_start), usename, current_query | |
FROM pg_stat_activity | |
WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%' | |
ORDER BY query_start desc; | |
-- show running queries (9.2) | |
SELECT pid, age(clock_timestamp(), query_start), usename, query | |
FROM pg_stat_activity | |
WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%' |
(by @andrestaltz)
If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.
import pandas as pd | |
import pandas.io.sql as sqlio | |
import psycopg2 | |
conn = psycopg2.connect("host='{}' port={} dbname='{}' user={} password={}".format(host, port, dbname, username, pwd)) | |
sql = "select count(*) from table;" | |
dat = sqlio.read_sql_query(sql, conn) | |
conn = None |
If you are getting this in gdb on macOS while trying to run a program:
Unable to find Mach task port for process-id 57573: (os/kern) failure (0x5).
(please check gdb is codesigned - see taskgated(8))
gdbc
)#!/usr/bin/env python3 | |
from decimal import Decimal | |
import re | |
import yaml | |
from yaml.composer import Composer | |
from yaml.constructor import SafeConstructor | |
from yaml.parser import Parser | |
from yaml.reader import Reader | |
from yaml.resolver import BaseResolver, Resolver as DefaultResolver |
OP_CHECKDATASIG and OP_CHECKDATASIGVERIFY check whether a signature is valid with respect to a message and and a public key. The message is restricted to exactly 256 bits, if longer messages are to be signed, it is recommended to sign the messages hash.
OP_CHECKDATASIG permits data to be imported into a script, and have its validity checked against some signing authority such as an "Oracle".
OP_CHECKDATASIG and OP_CHECKDATASIGVERIFY are designed to be implemented similarly to OP_CHECKSIG [1]. Conceptually, one could imagine OP_CHECKSIG functionality being replaced by OP_CHECKDATASIG, along with a separate Op Code to create a hash from the transaction based on the SigHash algorithm.
#!/bin/sh | |
script_dir="contrib/devtools" | |
files_to_commit=$(git diff-index --cached --name-only --diff-filter=d HEAD) | |
format_paths="src/esperanza src/snapshot" | |
for file in ${files_to_commit} | |
do | |
for path in $format_paths | |
do |
#!/usr/bin/env bash | |
set -Eeuo pipefail | |
trap cleanup SIGINT SIGTERM ERR EXIT | |
script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" &>/dev/null && pwd -P) | |
usage() { | |
cat <<EOF | |
Usage: $(basename "${BASH_SOURCE[0]}") [-h] [-v] [-f] -p param_value arg1 [arg2...] |