Python

“Eventually I got better – I started making my own mistakes.”

Install pip3

# apt-cache search python3-pip
python3-pip - Python package installer
root@sysmgmt:~# apt-get install python3-pip
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  binutils binutils-common binutils-x86-64-linux-gnu b
...edited...

Data Structures

>>> print ("this is a {LENGTH} {STRING} print").format(LENGTH='short', STRING='test')
this is a short test print
>>> 

Virtual Environment

python3 -m venv <venv name>
 
eg.
$ python3 -m venv stuff-env
 
 
# EACH time you will need to run this to avtivate the virtual env:-
 
$ source stuff-env/bin/activate
(stuff-env) $ 

pip freeze shows current modules, so echo this to requirements.txt to automatically load modules

pip freeze > requirements.txt

To quit the venv, use deactivate command (which venv adds to your path)

$ deactivate
$

requirements.txt file

Specific versions of packages can be installed from a requirements.txt file, this avoids pip installing a module in a venv which is a later release than the code was written for:-

$ cat requirements.txt
Jinja2==2.11.2
PyYAML==3.13
SQLAlchemy==1.3.16
$ pip install -r requirements.txt

rb/python.txt · Last modified: 21/04/2020 15:13 by andrew