A lot of people use Python as a replacement for shell scripts, using it to automate common system tasks, such as manipulating files, configuring systems, and so forth. This article aims to describe accepting Script Input via Redirection, Pipes, or Input Files.
Problem – To have a script to be able to accept input using whatever mechanism is easiest for the user. This should include piping output from a command to the script, redirecting a file into the script, or just passing a filename, or list of filenames, to the script on the command line.
Python’s built-in fileinput module makes this very simple and concise if the script looks like this.
Code #1 :
Then input to the script can already be accepted in all of the previously mentioned ways. If the script is saved and make it executable then the one can get the expected output using all of the following:
Code #2 :
The fileinput.input() function creates and returns an instance of the FileInput class. In addition to containing a few handy helper methods, the instance can also be used as a context manager. So, to put all of this together, if one wrote a script that expected to be printing output from several files at once, one might have it include the filename and line number in the output, as shown in the code given below –
Code #3 :
/etc/passwd1 /etc/passwd2 /etc/passwd3 <other output omitted>
Using it as a context manager ensures that the file is closed when it’s no longer being used, and one leveraged a few handy FileInput helper methods here to get some extra information in the output.
- Run python script from anywhere in linux
- Python Script to Restart Computer
- Get directory of current Python script
- Python Script to Logout Computer
- Python Script to Shutdown Computer
- Autorun a Python script on windows startup
- Python | Add Logging to a Python Script
- Python script to open a Google Map location on clipboard
- Run Python script from Node.js using child process spawn() method
- Taking input in Python
- Taking input from console in Python
- Python | Get a list as input from user
- Vulnerability in input() function – Python 2.x
- Take Matrix input from user in Python
- PyQt5 Input Dialog | Python
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to firstname.lastname@example.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.