If you run the program again, it starts with a clean slate. Other programs are persistent:
September 07, As a system administrator, you run across numerous challenges and problems. Managing users, disk space, processes, devices, and backups can cause many system administrators to lose their hair, good humor, or sanity. Shell scripts can help, but they often have frustrating limitations.
This is where a full-featured scripting language, such as Python, can turn a tedious task into an easy and, dare I say it, fun one. The examples in this article demonstrate different Python features that you can put to practical use.
About modules A module is an important Python concept. Basically, a module is a resource you import in order to use it. This process is comparable to taking a piece of paper out of a file cabinet and putting it on your desk, ready for use. You import modules using the import command, which appears at the top of each of the example programs.
Modules are available for database connectivity, network programming, operating system services, and hundreds of other useful areas. Put Python to work Python has many features to recommend it: Many users find its syntax much more English-like than other scripting languages.
Python has been around a long time, which means its code is stable, lots of modules add functionality, and robust documentation is available on the Web. Python is a full-featured, robust programming language and, as such, it has tons of features. Learning it could be a task of epic proportions.
However, remember that many Python features, such as the GUI toolkits, are of limited value to system administrators.
They demonstrate the skills you need to effectively write Python scripts to manage systems. Notes on the examples Each example includes a try: This is an implementation of rudimentary error handling. These examples were run on Python 2. The nature of Python scripts is that they can be easily modified and customized without needing to recompile code.
Search for files and show permissions in a friendly format The first example program see Listing 1 searches for files that match a pattern based on user input and displays the results to the screen, along with the permissions assigned to the particular files. The example shows you how to take a system command and make it better or at least more customized.
The script basically performs three tasks: Get the search pattern from the user. Present the results to the user. In writing the script, constantly ask yourself this question, "Which task is this code supporting?
Search for files and list results with file permissions import stat, sys, os, string, commands Getting search pattern from user and assigning it to a list try: Ask the user for a search pattern lines Print a listing of files found lines Using the stat module, get permissions for each file found and display them to the screen lines When the program is run, the output looks like that shown in Listing 2.
Perform operations on a tar archive that is based on menu selection The previous example prompted the user for a search pattern to use.
Another way to get information from the user is through a command-line argument.Overview. Learn the language used at NASA, Instagram, Dropbox, and other big-data companies as you build professional-grade apps in Python.
Throughout this intensive course, you will study professional software development techniques and practices as you advance your skills in Python. A Foolish Consistency is the Hobgoblin of Little Minds. One of Guido's key insights is that code is read much more often than it is written.
The guidelines provided here are intended to improve the readability of code and make it consistent across the wide spectrum of Python code. SD Card. The Raspberry Pi needs to store the Operating System and working files on a micro SD card (actually a micro SD card for the B+ model, but a full size SD card if you’re using a B model).
You are here: Home ‣ Dive Into Python 3 ‣ Difficulty level: ♦♦♦♦♢ Packaging Python Libraries You’ll find the shame is like the pain; you only feel it once. — Marquise de Merteuil, Dangerous Liaisons Diving In. Real artists ship. Or so says Steve Jobs. Do you want to release a Python script, library, framework, or application?
SD Card. The Raspberry Pi needs to store the Operating System and working files on a micro SD card (actually a micro SD card for the B+ model, but a full size SD card if you’re using a B model).
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