Python

Learning Python scratch pad

Vim as Python IDE

Ubuntu comes with vim-tiny package that has most of things disabled, so get it uninstalled

sudo apt-get purge vim-tiny
sudo apt-get install vim         #py3 support
sudo apt-get install vim-nox-py2 #py2 support
vim --version | grep python  #verify you should see eg: +python -python3

Optimally you may need to set alternatives

 sudo update-alternatives --set vim /usr/bin/vim.nox-py2

Now, open vim and check :python import sys; print(sys.version) you should see similar output

2.7.12 (default, Nov 19 2016, 06:48:10)
[GCC 5.4.0 20160609]

Simple HTTP Server

It provides the local files browser over http protocol and access logs

sudo python -m SimpleHTTPServer 80

print()

Print in v3 is a function, it uses arguments with variables like below:

%s - String (or any object with a string representation, like numbers)
%d - Integers
%f - Floating point numbers
%.<number of digits>f - Floating point numbers with a fixed amount of digits to the right of the dot.
%x/%X - Integers in hex representation (lowercase/uppercase)

Eaxmple:

print("%s is %d years old." % (name, age))

Install Selenium lib on Ubuntu

$ which python python3
/usr/bin/python
/usr/bin/python3
sudo apt-get install python3-pip # install pip for python3
sudo python3 -m pip install -U selenium # install selenium for python3
sudo python3 -m pip install -U pip #upgrade pip

Install geckodriver on Ubuntu

It's required if you use Selenium in Python, webdriver function:

default_browser = webdriver.Firefox()

Install

## Geckodriver (verified on Ubuntu 16.04 running on Vagrant)
wget https://github.com/mozilla/geckodriver/releases/download/v0.21.0/geckodriver-v0.21.0-linux64.tar.gz
sudo sh -c 'tar -x geckodriver -zf geckodriver-v0.21.0-linux64.tar.gz -O > /usr/bin/geckodriver'
sudo chmod +x /usr/bin/geckodriver
rm geckodriver-v0.21.0-linux64.tar.gz

## Chromedriver
wget https://chromedriver.storage.googleapis.com/2.29/chromedriver_linux64.zip
unzip chromedriver_linux64.zip
sudo chmod +x chromedriver
sudo mv chromedriver /usr/bin/
rm chromedriver_linux64.zip

Login and scrape website

Script below demonstrate usage of Selenium automation through Mozilla Geckodriver. It will open Firefox, navigate to a give URL, fill in a form, click a login button and take a screenshot.

Credentials file

cat creds.yaml
wpUser: user
wpPass: pass123

Main script

#!/usr/bin/python3
from selenium import webdriver
import yaml
driver = webdriver.Firefox()
creds = yaml.safe_load(open('creds.yaml','r'))
driver.get('http://wiki.ciscolinux.co.uk/index.php?title=Special:UserLogin&returnto=Main+Page')

user_field = driver.find_element_by_name("wpName")
pass_field = driver.find_element_by_name("wpPassword")
user_field.send_keys(creds['wpUser'])
pass_field.send_keys(creds['wpPass'])
# find login button and click on it
driver.find_element_by_name('wploginattempt').click()
driver.save_screenshot('screenshot.png')
driver.close

References

• A Beginner's Python Tutorial Wikibooks
• List of free Python learning resources
• VIM and Python - a Match Made in Heaven Vim as Python IDE
• Vundle Vim bundle/plugins manager