How to do it...

1. A number of options are available for the Python command-line call. To enter interactive mode, call Python with no additional options:

      $ python
      Python 3.6.3 |Anaconda, Inc.| (default, Oct 13 2017, 12:02:49) 
      [GCC 7.2.0] on linux 
      Type "help", "copyright", "credits" or "license" for
      more information. 
      >>>

1. To execute a regular Python program with no special options, add the program name:

      $ python <script>.py

1. To execute a series of Python commands without entering interactive mode or calling a file, use -c:

      $ python -c "print('Hello World')"

1. To call a Python module as a standalone program, use -m:

      $ python -m random

1. Discussion of the other possible options is provided in the following section.