Python is a high-level, general-purpose, interpreted programming language. It can be used to do some different purpose: from managing large data, simple to complex calculations to very specific objectives by using the pre-written packages.
There are 2 most common used versions of Python: Python 2 (current version is 2.7) and Python 3 (current version is 3.5). The 2 versions are different in some syntax, which Python 2 is the stable version while Python 3 is the developing version.
I. Basics syntax
A python script can be invoked by the first line ‘#!/usr/bin/python’ similar to using Perl.
Running a python program: we will start with how to run a python program Helloworld.py as below:
#!/usr/bin/python hello = 'Hello World!' print hello
To run a program in python we use:
Addition flags can be used to calibrate the running process, details can be found here. A useful flag is -i (interactive mode) which allows you to control the variable and running process.
Command locals() is used to give a dictionary of local variables. All of the variables with __ are python pre-defined variables. This mode helps to check the variables during your program.
Using as a calculator: Basic mathematics operation can be used in Python, for example:
For more complex calculations, a package named numpy is used to complete these task. A tutorial in using Python package will be presented later.
II. Using external commands
Python allows running external commands using either module: os and subprocess.
import os os.system('ls -l')
from subprocess import call call(['ls','-l'])
Nguyen Cong Nghia – IESAS