Python Operator Precedence

by XDK 12. August 2019 06:10

Note: Operators in the same row are evaluate left to right except ** (Exponentiation) which is right to left binding

Tags:

Python

Essential Installs to setup python development environment

by XDK 9. August 2019 15:09

Install commands:

Generic update:
sudo apt update

mySQL client install:
sudo apt install mysql-client

** mySQL login command **
mysql -h <RDS endpoint> -u <user name> -p <password>

apache server install:
sudo apt install apache2

python essentials install:
sudo apt install python3

** Refer here for pip install **

sudo apt-get purge python-pip
wget https://bootstrap.pypa.io/get-pip.py
sudo python get-pip.py

sudo apt install python-pip
sudo pip install mysql-connector-python
sudo pip install pymysql

sudo pip install boto3

** Boto3 is the Amazon Web Services (AWS) Software Development Kit (SDK) for Python, which allows Python developers to write software that makes use of services like Amazon S3 and Amazon EC2. You can find the latest, most up to date, documentation at our doc site, including a list of services that are supported. **

Tags:

Amazon Web Service | General | Python

File "/usr/bin/pip", line 9, in <module> from pip import main ImportError: cannot import name main

by XDK 9. August 2019 14:46

Exception:

File "/usr/bin/pip", line 9, in <module> from pip import main ImportError: cannot import name main

Explanation:

The exception appears after installing python-pip in the environment. looks like, the get-pip.py script from github is outdated which may be the reason for the exception.

Quick Fix:

Reinstalling python-pip from https://bootstrap.pypa.io website fixed the exception.

sudo apt-get purge python-pip
wget https://bootstrap.pypa.io/get-pip.py
sudo python get-pip.py

Tags:

Amazon Web Service | Python

What is serialization and Deserialization Python?

by XDK 7. August 2019 03:43

Explanation:

Python object serialization and deserialization is an important aspect of any non-trivial program. If in Python you save something to a file, if you read a configuration file, or if you respond to an HTTP request, you do object serialization and deserialization.

Serialization refers to the translation of object state into bytes to send it over the network or store it in hard disk. We need serialization because the hard disk or network infrastructure are hardware component and we cannot send objects because it understands just bytes and not objects

Pickling and Unpickling in Python.

Pickling in python refers to the process of serializing objects into binary streams, while unpickling is the inverse of that. It’s called that because of the pickle module in Python which implements the methods to do this.Pickling is useful when you want to save the state of your objects and reuse them at another time without losing any instance specific data. If you are using large files, CPickle is recommended. CPickle is implemented in C, making it much faster.

 

Tags: ,

Python

Disclaimer

The information provided here is based on my expreriences, troubleshooting and online/offline findings. It can be used as is on your own risk without any warranties and I impose no rights.

About the author

My name is Xavier Dilip Kumar Jayaraj and I am a Software Configuration Management Engineer with a background in application development, Build & packaging using Install Shield.

Profile in LinkedIn , PCEP-Certified , Azure-DevOps-C1

DevOps Tools

ALM tools:
Azure DevOps
IBM Rational
CA Agile Central-Rally
CollabNet VersionOne

Configuration tools:
• Puppet
• CHEF
• AWS OpsWorks
• Ansible

Build automation tools:
Apache Ant 
Apache Maven
Boot
Gradle
Grunt
MSBuild
Waf

Continuous Integration tools:
Bamboo
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Hudson
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Testing tools:
Selenium
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ApacheJMeter
QTest

Version control system tools:
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Team Foundation Server
GIT
Mercurial
Perforce

Code review tools:
Crucible
Gerrit
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Bitbucket Server

Continuous Delivery/release management tools:
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Quotes I Like

"Failure will never overtake me if my determination to succeed is strong enough."  - Dr. APJ. Abdul Kalam

"Always be yourself, express yourself, have faith in yourself, do not go out and look for a successful personality and duplicate it." - Bruce Lee

"Technology is just a tool. In terms of getting the kids working together and motivating them, the teacher is the most important." - Bill Gates

"Innovation distinguishes between a leader and a follower." - Steve Jobs

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