This course will focus on learning programming using the Python language . This is a modern programming language that works on all common operating systems.

Currently, there are two versions of the Python language: the older, but still more widespread version 2 and the modern version 3. They are not completely compatible with each other: a program written for one version of the language may not be executable for another version. But basically both versions are very similar.

We will use version 3 of this language, some of the examples used will not work with version 2. The latest version of the languageis what you need to install at home by downloading this version from the website www.python.org.

You can start the python interpreter from the command line:

$python3

Be careful - the python command will launch version 2 interpreter, which we will not work with. On Windows, you can use the menu item “Python (command line)”

You will see a command prompt similar to the following: 

Python 3.1.2 (r312:79147, Jun 12 2010, 15:29:06)

[GCC 4.4.3 20100316 (ALT Linux 4.4.3-alt2)] on linux2

Type "help", "copyright", "credits" or "license" for more information.

>>>

Feel free to enter the commands and enjoy the results. What can you enter? A few examples:

>>> 2 + 2

4

>>> 2 ** 100

1267650600228229401496703205376

>>> 'Hello' + 'World'

'HelloWorld'

>>> 'ABC' * 100

'ABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABC ABCABCABCABCABCABCABCABCA BCABCABCABCABCABCABCABCABCABCABCABCABC ABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABC ABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABC ABCABCABCABCABCABCABCABCABCABCABCABCABCABCABCABC'

‍

The first command calculates the sum of two numbers, the second command calculates 2 to the power of 100, the third command performs the concatenation operation on the strings, and the fourth command prints the string 'ABC' repeated 100 times.

Want to finish working with Python? Enter the command exit() (exactly, with parentheses, since it is a function), or press Ctrl+D.