Python Programming Notes

Here are my notes from starting to use and learn the python programming language. I am only focusing on Python 3 at this time.

The subprocess module allows you to spawn new processes, connect to their input/output/error pipes, and obtain their return codes.
Some key points:

• The command to be run arguments “args” should be passed in as a list, the list components should not contain any white space. e.g.:
  • args=[cmd, '-I', 'lanplus', '-H', BMC_IP, “-U”, User_Name, '-f', PW_file_location, 'power', power_ctl], where components in quotation are text and those without are variables.
  • With argument type the input option shell=False must be set. This is the default default and preferred option.
• stdout=subprocess.PIPE In order to capture the command output from the function. Otherwise it will go to the standard output stream, e.g. the terminal screen.
  • the output value can be captured from subprocess.stdout, this is in byte format.
  • It can be captured and converted to text format subprocess.stdout.decode('utf-8')
  • The return code of the function can be capture from output using subprocess.returncode

My python based back-up scripts are located here: python_backup_scripts

• Python Docs - Subprocess management
• Python | Execute and parse Linux commands
• 10+ practical examples to learn python subprocess module
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• 5 Ways to Convert bytes to string in Python
• How to Pass Arguments to a Python Script from the Command Line
• How to create, read, append, write to file in Python
• Python Exception Handling Using try, except and finally statement