How to solve the issue of printing with a hp Officejet on a Mac

I have an old hp Officejet 2620 printer that works very fine. I recently got this issue when trying to print. I always get this error message “waiting for printer to become available” and no way to solve it, even after resetting the whole printer setting.

I finally found the full solution.

  • Reset the Mac printing system
    • On your Mac, choose Apple menu > System Preferences, then click Printers & Scanners.
    • Press and hold the Control key as you click in the list at the left, then choose “Reset printing system” from the menu that appears.
  • Before adding the printer again, delete all files from the /Library/Printer. That was the part missing in my case.
    • From the menu bar in the Finder, choose Go > Go to Folder. Type /Library/Printers/ and click Go.
    • The Printers folder opens. Choose Edit > Select All, which selects all items in the Printers folder.
    • Choose File > New Folder with Selection, which puts all of the selected items into a new folder named New Folder With Items. To save storage space, you can delete this folder.
  • Now you can add your printer again, following your printer instructions.

Sources :

Hacking Covid 19 : Hackathon HEC

I had the pleasure to participate a a mentor in the hackathon “Hacking Covid 19“.

This hackathon was organized mostly by HEC, Polytechnic and SciencesPo schools. It was in virtual mode as covid 19 crisis was still here.
This was a huge success.

  • 1400 participants from 52 countries
  • 105 projects were submitted
    • 18 of them will get help from this hackathon

Here are the 3 winners.

Granny helps elderly people to stay in touch with the family as family couldn’t visit the manymore.

DIO, Do It Yourself, helps linking together SMBs and find the best partners to keep producing.

Safeline develops a mobile application to manage queue lines in shops and avoids long queues.

IBM gave access to IBM Cloud and Call for Code starting kits.

During this hackathon, I helped many projects among them Safeline and Granny. As a mentor, I helped them in a global way and I provide a lot of technical help, around IBM Cloud when it was needed.

Participating in hackathons is a way to help projects, show that IBM can help when needed, provide a huge number of resources, and free resources too, in IBM Cloud. It’s also a way to show IBM Cloud features and the beauty of them as we clearly have a deficit of recognition compared to Amazon, Azure and Google.

I enjoyed this hackathon and other ones. I met a lot of nice people, looking to find ways to help tackle Covid 19 impacts. I increased a lot my LinkedIn contact list also with people coming from a lot of different areas and countries.

Learning path to Data Science

Many people asked me what is the path and what they should learn to become Data Scientist or to understand Data Science (DS). Here is the learning I did and some meaningful on this subject.

I will update this post from time to time. Don’t hesitate to let me know about your own course or post in comments.


Machine Learning from Coursera
This course in Coursera has been followed by more than 2 million people, yes, 2 millions ! It is very nicely done and make Data Science easy by the way Andrew Ng teaches it.
Usually when I talked about this course, people already knowledgeable in DS already knows about it.
This course is all about theories behind Machine Learning (ML) and there are some extensive hands on on Matlab/Octave. Be prepare to learn or use about math (matrices, derivatives, functions) and some coding too.
Link :
This site is managed by IBM and there are a lot of interesting courses. Moreover you can get $1200 worth of credit in the IBM Cloud to train and test and your learning.
Data Analysis with Python : Learn how to analyze data using Python. This course will take you from the basics of Python to exploring many different types of data. You will learn how to prepare data for analysis, perform simple statistical analyses, create meaningful data visualizations, predict future trends from data, and more!
Machine Learning with Python : Learn about how to use Python Libraries. This is a good follow up to have Python hands on after the Machine Learning Course from Coursera.

Posts is a great source of DS posts

10 Machine Learning Methods that Every Data Scientist Should Know : A good list of all subjects in DS

Watson Ecosystem and Portfolio

Here is my main presentation of Watson Ecosystem and Portfolio I use for client workshops. Feel free to share, download the PDF and ask questions, I will enjoy giving you details on the wonderful world of Watson.

Upgrade your IBM Cloud account from free to trial

you can easily upgrade your account from free to trial and get a $1200 credit in IBM Cloud at the same time.

For this, open an account in Cognitive Class, using your IBM Id.

Then register for a class, whichever you want. How to build a chatbot for instance. You can now claim your Gift.

Now log in in your IBM Cloud account and go to your account settings. Click on “Apply Code” and enter your code.

You now have a trial account with $1200 credit. You cannot see this credit by itself in the Account page as it is in the Trial account itself.

IBM Watson Services : what is included in your free account ?

You can have a free account in IBM Cloud without time limitations and only usage limitation. Let’s see what you can do with this account and you will realize you can already do a lot with it !

One limitation to be aware is that a service is deleted after 30 days of inactivity. You will get an email to warn you of the deletion a few days before. If you want to keep using it, just go to the service and use it once for another 30 days.

I will list what is included in each Watson services to show you you can start right now to develop with IBM before even starting to pay for anything.

Watson Assistant (WA)

Watson Assistant helps you develop dialogs and chatbot for any kind of use case. Here is what you can do.

  • 10,000 Messages/Month
  • AI-Based Intent and Entity Recognition
  • Entity Synonym Recommendations
  • Visual Dialog Edit with Simple Response Types (Text, Options, Images, etc…)
  • Prebuilt Content Available
  • Analytics Dashboard with 7 Days of Storage
  • 5 Dialog Skills, Each with 100 Dialog Nodes
  • Shared Public Cloud

This is already a lot to start a dialog bot, test it and use it with your firsts users.

Main part missing in the Lite plans :

  • Discovery skills that allows to go to Discovery for search directly from Assistant (Short Tail / Long Tail made easy)
  • Disambiguation
  • Intent Recommendations
  • Intent Conflict Detection
  • Service Desk Integrations

Watson Discovery (WDS)

Watson Discovery helps you index documents in a smart way and find useful information in them you couldn’t find another way. Here is what you can do.

  • 1,000 documents per month
  • 1 custom model
  • 500 element classification pages per month

A custom model is a new context model developed with Watson Knowledge Studio.

Visual Recognition

  • 1,000 Events per month towards:
    • Pre-trained model classification (General, Face, Food, Explicit) (images)
    • Custom Model classification (images)
    • Custom Model training (images)
    • 2 Custom Models
    • 1 Lite Plan instance per IBM Cloud Organization
    • Free Exports to Core ML

Language Translator (LT)

Language Translator helps you translate language in another language

  • 1,000,000 Characters per Month

Natural Language Understanding (NLU)

  • 30,000 NLU Items Per Month
  • 1 Custom Model

NOTE: A NLU item is based on the number of data units enriched and the number of enrichment features applied. A data unit is 10,000 characters or less. For example: extracting Entities and Sentiment from 15,000 characters of text is (2 Data Units * 2 Enrichment Features) = 4 NLU Items. A custom model refers to an annotation model developed with Watson Knowledge Studio.

Personality Insights (PI)

  • 1,000 API Calls per Month

Speech To Text (STT)

  • 100 Minutes per Month

Text To Speech (TTS)

  • 10,000 Characters per Month

Tone Analyzer

  • 2,500 API Calls per Month

How to start with IBM Cloud and IBM Watson : Create your account.

You may have seen some nice presentation on IBM Cloud and IBM Watson and want to try now yourself ? It’s very easy and you can get a lot of services for free to start your projects.

IBM Cloud registration

IBM Cloud registration is easy and give you access to 61 services available in lite mode and covers the full range of services : Development, Storage, Databases, AI with Watson, API, …

Here is how to register. It is very simple. Go to and click on “Create an IBM Cloud account”. Fill in your email address and all details asked and click on “Create Account”. You may have a Captcha to answer, right now we don’t allow AI to create their own account 🙂

You will get an email to confirm your email address.

Click on “Confirm account”and here we go.

Click on “Log In”

You then have to accept the IBMid Account Privacy policy by clicking on “Proceed” after reading them.

You have now access to the IBM Cloud Dashboard !

Let’s see in the next post, what you can use for free and all the things you can play with.

How to upgrade TensorFlow in Watson Studio Jupyter Notebook

I recently wanted to learn more about TensorFlow and as a Watson Solution Architect, I am using Watson Studio Jupyter Notebooks. On my first test I had an error on the second command.

I realized I was using an old version. Let’s see how to upgrade to a newer version. Watson Machine Learning is using TensorFlow version 1.11 so I wanted to use the same one. Here are the steps.

#Install a pip package in the current Jupyter kernel
import sys
  !{sys.executable} -m pip install tensorflow==1.11.0

This will install tensorflow version 1.11. It should whow the download of the version. To check the version number, here is the command.

import tensorflow as tf

If you don’t get 1.11.0, you may need to restart the kernel.

Now everything is working.

Next step : configure directly an environment to select the components version.

Available Languages in Watson Services

I couldn’t find one page listing languages available in Watson Services, so let’s do one 🙂

This information is available but scattered in the middle of the documentation. Here is the list of languages available for each services.

Watson Assistant (WA)

Natural Language Understanding (NLU)

Custom model support is done through Watson Knowledge Studio (WKS)
Source :

Watson Discovery (WDS)

Basic support
• Discovery support includes:
• Document conversion
• Orchestration
• Discovery Tooling functionality
• Front-end API (excluding Front-end Query API)
• Language-optimized index
• Relevancy training
• Query expansion
• Stopwords
• Documentation in 9 languages: English, French, German, Japanese, Korean, Brazilian Portuguese, Spanish, Chinese Simplified, and Chinese Traditional.
• Enrichments
• Integration with IBM Watson™ Knowledge Studio custom models
• Language detection

Full support
Full support includes basic support, plus:
• Passage retrieval
• Translated IBM Watson™ Knowledge Studio interface
• All Natural Language Understanding (NLU) enrichments, plus metadata extraction. NLU enrichments are:
• Entity Extraction
• Keyword Extraction
• Category Classification
• Concept Tagging
• Semantic Role Extraction
• Sentiment Analysis
• Emotion Analysis (English only)

English-only support
The following features are currently supported in English only:
• Element Classification enrichment
• IBM Watson™ Discovery Knowledge Graph (beta)
• Document deduplication (beta)

Japanese-only support
The following feature is currently supported in Japanese only:
• Custom tokenization dictionaries

Watson Knowledge Studio (WKS)

Support includes the ability to add documents in these languages to a workspace, add dictionaries, run pre-annotation, use the ground truth editor to annotate documents, and train a machine learning model. When you select a language, the system applies language-specific templates to handle dictionary entries, text tokenization, and sentence segmentation.

Speech to Text (STT)

Text to Speech (TTS)

Watson Language Translator

Here is the list of direct translation

And the list of language detected

Natural Language Classifier (NLC)

Personality Insight

Tone Analyzer

Visual Recognition

The text detection in images doesn’t use a specific language. Here is the list of supported language for classification.

Watson Studio & associated tools

Watson Studio helps you develop your own models, so they are developed in your language.

Watson Studio, Watson Machine Learning, Watson Knowledge Center, Watson Openscale


The idea comes from Fredrik Stenbeck and I wanted an updated and complete version.

How to avoid Google to crawl a website

Add a robots.txt file at the root directory with the following content.

User-agent: * 
Disallow: /