A blog about computer science
You get this error with python when you try from numba import jit, jitclass
https://github.com/ogrisel/pygbm/issues/98
You only need to import differently jitclass :
From :
from numba import jitclass
You need to use now :
from numba.experimental import jitclass
This article describes a python implementation of bitcoin mining that relies on an algorithm based on a double hash SHA-256.
Miners on the bitcoin network should look for the nonce which is a 32-bit number. The miner will successively test several NONCEs (1,2,3 …. 10 ^ 32-1), for each of the nonce he creates the following header and hasher twice with a SHA-256 bit hash function.
| Field | Description | Size |
|---|---|---|
| version | Version | 4 |
| Hash previous block | 256-bit hash of the previous block | 32 |
| Merkle root | This is a hash on the data in the block. It is provided to the miner and it contains a summary of the transactions that are contained in the block. | 32 |
| time | A digital timestamp that represents the number of seconds since 1970-01-01T00: 00 UTC | 4 |
| bits | The current target in compacted format | 4 |
| nonce | 32-bit number (starts at 0) | 4 |
Once the hash obtained, the miner must then check that the hash obtained is lower than the target difficulty factor of the block. If the hash obtained is greater then the nonce is not the correct one, another must be tested.
If you are using a blockhain bitoin explorer (for example blocstream info), if we take for example block 671712:
In this case here is an algorithm in python which allows to mine this block:
In this simulation I display the header and the calculated hash as well as the hash rate.
The nonce to find for block 671712 was 4107802144
in hexadecimal : 0xf4d81620
This algorithm starts with a nonce = 4107802144 – 400 we will act as if we were very close to finding the block (400 double hashes are missing to find the block):
import hashlib
from hashlib import sha256
import time
import struct
import binascii
import datetime
from binascii import unhexlify, hexlify
from dateutil import parser
from datetime import datetime
from datetime import timedelta
nontrouve = True
dtprec = datetime.now()
inonc = 4107802134 - 400 #Starting 400 before the good nonce
resultat = []
while(nontrouve):
inonc +=1
if(inonc%50==0):
print(str(round(timedelta(seconds=1)/(datetime.now() - dtprec))) + ' H/s')
dtprec = datetime.now()
header_hex = (binascii.hexlify(struct.Struct('<L').pack(int('0x2fffe000',16))).decode() +
binascii.hexlify(binascii.unhexlify('000000000000000000078908d256fa7a9f97b2e1ea532fb1ce45ee4bf050d221')[::-1]).decode()+
binascii.hexlify(binascii.unhexlify('c504fc3a406f11c7c5b598da7f50916f4e298041e6f9b91535a80db113af109a')[::-1]).decode() +
binascii.hexlify(struct.Struct('<L').pack(int(hex(int(parser.parse('2021-02-22 15:14:22 GMT +1').timestamp())-3600),16))).decode() +
binascii.hexlify(struct.Struct('<L').pack(int("0x170cf4e3",16))).decode() +
binascii.hexlify(struct.Struct('<L').pack(int(hex(inonc),16))).decode())
header_bin = unhexlify(header_hex)
dt1 = datetime.now().strftime("%H:%M:%S.%f")
hash = hashlib.sha256(hashlib.sha256(header_bin).digest()).digest()
hexlify(hash).decode("utf-8")
hexlify(hash[::-1]).decode("utf-8")
hash=hexlify(hash[::-1]).decode("utf-8")
resultat.append([round(int(hash,16)/10**65)])
MAX_TARGET = int("00000000FFFF0000000000000000000000000000000000000000000000000000", 16)
Difficulty = 21724134900047.27
target = int(MAX_TARGET / Difficulty)
target32 = '{:0>64x}'.format(target)
if(int(hash,16) < int(target32,16)):
print('###########BLOC MINED###################')
print('HEADER=' + header_hex)
print('HASH=' + hash)
print('NONCE=' + str(inonc))
print('NONCE (hex)=' + hex(inonc))
print('###########BLOC MINED###################')
break
The output is :
1149 H/s 4405 H/s 4115 H/s 1534 H/s 3831 H/s 2392 H/s 4386 H/s 3165 H/s ###########BLOC MINED################### HEADER=00e0ff2f21d250f04bee45ceb12f53eae1b2979f7afa56d20889070000000000000000009a10af13b10da83515b9f9e64180294e6f91507fda98b5c5c7116f403afc04c53ebc3360e3f40c172016d8f4 HASH=000000000000000000062a949bc297739a12e639ba9e2107638b469afe11d0f8 NONCE=4107802144 NONCE (hex)=0xf4d81620 ###########BLOC MINED###################
https://en.bitcoin.it/wiki/Block_hashing_algorithm
When you try to lauchn the utility sdkmanager for android SDK you get the following error : Exception in thread “main” java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema
Solution is to install JDK 8 :
brew cask uninstall java brew tap homebrew/cask-versions brew cask install java8 touch ~/.android/repositories.cfg brew cask install android-sdk
In some case the right command is :
brew install openjdk@8
Little guide to setup android sdk from homebrew and install Android Command line tools
brew install --cask android-sdk
sdkmanager --help
https://formulae.brew.sh/cask/android-sdk
To solve this error Godot status != 0x8CD5 in RasterizerGLES2 – rasterizer_gles2.cpp a way to do it is to force using OPENGL2.1 with parameter --video-driver GLES2 the complete command is :
godot.exe --path pathproject --video-driver GLES2 -e
If you get this error modules/speech_to_text/register_types.cpp:2:10: fatal error: ‘object_type_db.h’ file not found you need to do this :
Go into directory source of GODOT and modules/speech_to_text :
File to open is register_types.cpp
You will see use of a header file
#include "object_type_db.h"
It changes between GODOT 2 and 3 from object_type_db.h to class_db.h
So chang it by :
#include "core/object/class_db.h"
Save and execute GODOT source compilation again it will works.
I get similar error on
modules/speech_to_text/stt_config.h:4:10: fatal error: ‘core/resource.h’ file not found
You need to open modules/speech_to_text/stt_config.h and modify :
#include "core/resource.h"
By :
#include "core/io/resource.h"
Also i get modules/speech_to_text/stt_error.h:4:10: fatal error: ‘core/object.h’ file not found
so i do the following in stt_error.h :
#include "core/object.h" #include "core/ustring.h"
#include "core/object/object.h" #include "core/string/ustring.h"
https://docs.godotengine.org/en/3.0/development/compiling/compiling_for_osx.html
If you get this type of errors TypeError: can_build() takes 1 positional argument but 2 were given when trying to compile Godot you have to do this :
When i tried to compile with scons i got this errors :
scons: Reading SConscript files ...
Automatically detected platform: osx
Building for macOS 10.12+, platform x86-64.
TypeError: can_build() takes 1 positional argument but 2 were given:
File "/Users/myuser/godot/SConstruct", line 556:
if config.can_build(env, selected_platform):
First check you version of scons by launching :
scons -v
It will give you the scons path :
SCons path: ['/usr/local/Cellar/scons/4.1.0.post1/libexec/lib/python3.9/site-packages/SCons']
You then notice the use of python 3.9
You have to update your python to 3.9 :
Update Python easy update to Python 3.9 with homebrew – To update Mac os python from an older version to the latest python example python 3.9.1 you can do the folowing :
This article briefly describes how to replace its version of python on Mac. I wrote a similar article some time ago.
I used Homebrew to get the latest python as describe on https://formulae.brew.sh/formula/python@3.9:
brew install python@3.9
python --version Python 3.8.5 python3 --version Python 3.8.5
You see that it stays on the older version.
I had to first verify where my python command is pointing, by launching :
which python
It gave me in my case:
/Users/myuser/.pyenv/shims/python
You need also to verify where is python3 command if you have different versions :
which python3
I get :
/Users/myuser/.pyenv/shims/python3
I need to replace the version of the both command python and python3 by launching :
ln -s -f /usr/local/bin/python3.9 /Users/myuser/.pyenv/shims/python3
And also launch :
ln -s -f /usr/local/bin/python3.9 /Users/myuser/.pyenv/shims/python
The you can test it works :
python --version Python 3.9.1 python3 --version Python 3.9.1
You need to localize the module that is bad in GODOT modules directory
For example i localize speech_to_text that was bad in config.py
So i directly modify config.py from this directory from can_build(env) to can_build(env, platform):
import os # system()
def can_build(env, platform):
if platform == "x11":
has_pulse = os.system("pkg-config --exists libpulse-simple") == 0
has_alsa = os.system("pkg-config --exists alsa") == 0
return has_pulse or has_alsa
elif platform in ["windows", "osx", "iphone", "android"]:
return True
else:
return False
def configure(env):
pass
And it works :
godot % scons scons: Reading SConscript files ... Automatically detected platform: osx Building for macOS 10.12+, platform x86-64. YASM is necessary for WebM SIMD optimizations. WebM SIMD optimizations are disabled. Check if your CPU architecture, CPU bits or platform are supported! Checking for C header file mntent.h... no scons: done reading SConscript files. scons: Building targets ... [Initial build] Compiling ==> platform/osx/crash_handler_osx.mm [Initial build] Compiling ==> platform/osx/os_osx.mm [Initial build] Building RD_GLSL header: "servers/rendering/renderer_rd/shaders/canvas.glsl.gen.h" [Initial build] Building RD_GLSL header: "servers/rendering/renderer_rd/shaders/canvas_occlusion.glsl.gen.h" [Initial build] Building RD_GLSL header: "servers/rendering/renderer_rd/shaders/scene_forward.glsl.gen.h" [Initial build] Building RD_GLSL header: "servers/rendering/renderer_rd/shaders/canvas_sdf.glsl.gen.h"
This article briefly describes how to replace its version of python on Mac. I wrote a similar article some time ago.
Update Python easy update to Python 3.9 with homebrew – To update Mac os python from an older version to the latest python example python 3.9.1 you can do the folowing :
This article briefly describes how to replace its version of python on Mac. I wrote a similar article some time ago.
I used Homebrew to get the latest python as describe on https://formulae.brew.sh/formula/python@3.9:
brew install python@3.9
python --version Python 3.8.5 python3 --version Python 3.8.5
You see that it stays on the older version.
I had to first verify where my python command is pointing, by launching :
which python
It gave me in my case:
/Users/myuser/.pyenv/shims/python
You need also to verify where is python3 command if you have different versions :
which python3
I get :
/Users/myuser/.pyenv/shims/python3
I need to replace the version of the both command python and python3 by launching :
ln -s -f /usr/local/bin/python3.9 /Users/myuser/.pyenv/shims/python3
And also launch :
ln -s -f /usr/local/bin/python3.9 /Users/myuser/.pyenv/shims/python
The you can test it works :
python --version Python 3.9.1 python3 --version Python 3.9.1
This article briefly describes how to replace its version of python on Mac. I wrote a similar article some time ago.
Comment faire un ping sur Filius ? Filius est un logiciel de simulation de réseau. Ce premier article présente la création d’un réseau ad hoc entre deux ordinateurs et l’utilisation la commande ping.
Ajouter les 2 ordinateurs et les relier par un câble réseau.
Configurer le nom et l’adresse IP des ordinateurs, soit “Ordinateur A” : 198.168.0.10 et “Ordinateur B” : 198.168.0.20
Démarrer et installer la ligne de commande sur l’ordinateur A en cliquant dessus.
Utiliser la commande ping 192.168.0.20. Ping est une commande qui envoie des paquets réseau vers l’adresse demandée et qui mesure les temps de réponse.
https://www.ionos.fr/digitalguide/serveur/outils/commande-ping/
https://fr.wikipedia.org/wiki/Ping_(logiciel)
http://128mots.com/index.php/en/category/non-classe-en/
http://128mots.com/index.php/category/non-classe/
starthost failed, but will try again: config: please provide an ip address
❌ Exiting due to GUEST_PROVISION: Failed to start host: config: please provide an IP address : Error with kubernetes and minikube minikube
So, if you are trying to start the kubernetes tutorial from https://kubernetes.io/fr/docs/setup/learning-environment/minikube and you want to start minikube by the command :
minikube start
Then, you are getting this error :
minikube v1.17.1 sur Darwin 10.15.7 ✨ Utilisation du pilote ssh basé sur le profil existant 👍 Démarrage du noeud de plan de contrôle minikube dans le cluster minikube 🤦 StartHost failed, but will try again: config: please provide an IP address 😿 Failed to start ssh bare metal machine. Running "minikube delete" may fix it: config: please provide an IP address ❌ Exiting due to GUEST_PROVISION: Failed to start host: config: please provide an IP address 😿 If the above advice does not help, please let us know: 👉 https://github.com/kubernetes/minikube/issues/new/choose
And, the best way to solve this problem is to run the following command. Also you can find information on https://minikube.sigs.k8s.io/docs/drivers/ssh/
If you are running with docker you will find on https://minikube.sigs.k8s.io/docs/drivers/docker/ what i have done is to delete the last minkube cluster and rerun with the command specify the docker :
minikube delete
You will get :
🔄 Désinstallation de Kubernetes v1.20.2 à l'aide de kubeadm… 🔥 Trying to delete invalid profile minikube
And then :
minikube start --driver=docker
This is working :
😄 minikube v1.17.1 sur Darwin 10.15.7 ✨ Utilisation du pilote docker basé sur la configuration de l'utilisateur 👍 Démarrage du noeud de plan de contrôle minikube dans le cluster minikube 🚜 Pulling base image ...
