python toolkit

pip

install pip

on mac, we can use homebrew to install pip brew intall pip, python3 is installed with pip, so you don’t need to install pip, for python2.x, you can install by download get-pip.py

sudo python get-pip.py

update pip

pip install -U pip

install package

pip install requests
pip install requests=1.0
pip install 'requests>=2.1'  note '' is required

removing a package

pip uninstall requests

pip list

#### pip show requests #### pip search query

pip freeze

pip freeze > requirements.txt

save your project’s dependencies in requirements.txt

pip install -r requirements.txt

install all packages listed in requirements.txt

virtualenv

python install package systemwides, so we need virtualenv to encapslate the package into project scope, basically we will create a virtualenv for every project

installation

sudo pip install virtualenv

usage

create a new virtualenv in directory .virtualenvs

mkdir ~/.virtualenvs
cd ~/.virtualenvs

virtualenv newproject

// activate virtualenv

source newproject/bin/activate  //activate is a shell script

//now install package, you don't need sudo anymore, all the package are installed in the virtualenv

pip install pylint 

install with interpreter

virtualenv py3project --python=python3.4

deactivate the virtualenv

deactivate directly

best prectise

keep your virtual envrionments separate from your projects

prjects contain your source code under version control virtialenv contain libraries, tools, python interpreter, keep them in a directory like ~/.virtualenvs

virtualenvwrapper

workon: lists enviroments

workon projectname: Activate enviroment, switch to project

mkvirtualenv, rmvirtualenv: create, remove virtualenv

setvirtualenvproject: bind the virtual env to the project

system-wide install

sudo pip intall virtualenvwrapper
edit ~/.profile

source /usr/local/bin/virtualenvwrapper.sh
export PROJECT_HOME=$HOME/dev

default virtualenv location: ~/.virtualenvs

usage

mkvirtualenv myenv    # create a new virtualenv

cd ~/work/projects/myproject  # go to my project

setvirtualenvproject  # this couple my project with virtualenv

workon myenv      # jump to myproject and activate the virtualenv

mkproject sample

this create new virtualenv
create project
bind the env to the project
and move to the project

debug

import pdb
pdb.set_trace()

to enable debug in python, use pdb module

def main():
	local_variable= 'test'
	import pdb
	pdb.set_trace()
	for _ in range(10):
		print local_variable

if __name__ == '__main__':
	main()

pdb command

l : list the current cursor n : next step over s : step into h : help w : current stacktrace c : continue b : set break point b my_module:58 this will set breakpoint on line 58 in file my_module

sphinx document generator

installation:

pip install sphinx

usage:

sphinx-quickstart