Python Basic Syntax

Python is an interpreted programming language, this means that as a developer you write Python (.py) programs in a text editor and use the Python interpreter to execute it directly by using either one of the following two commands, where “HelloWorld.py” is the name of your Python program: 

shell> /usr/bin/python HelloWorld.py
shell> python HelloWorld.py

A Python program can be built as follows:
  1. Sign in to the server “undcemcs02.und.edu,” and navigate to the directory where you want to save your Python program.
  2. Write the first Python program, called HelloWorld.py, which can be done in any text editor.
  3. Execute the program. 
shell> cat HelloWorld.py
print "Hello, World!"

shell> python HelloWorld.py
Hello, World!

Python Comments
Python has commenting capability for the purpose of in-code documentation. Comments start with a #, and Python will render the rest of the line as a comment.

Python Variables
Variables are containers for storing data values. In Python, variables are created when you assign a value to it. Python has no command for declaring a variable. A variable is created the moment you first assign a value to it. 

shell> cat Test.py
x = 4          # x is of type int.
x = "Sally"    # x is now of type str.
print( x )

shell> python Test.py
Sally


Review: Python Programming Language
    Which is a valid Python comment?

      % This is a Python comment.
      # This is a Python comment.
      /* This is a Python comment. */
      <!-- This is a Python comment. -->
Result:        




      Maybe if we tell people the brain is an app,    
      they’ll start using it.