Popular Python recipes tagged "utilities"

Unix tee-like functionality via a Python class (Python)

2017-03-31T14:30:30-07:00

Python recipe 580767 by Vasudev Ram (cli, command, commandline, linux, python, tee, unix, utilities, windows).

The Unix tee commmand, when used in a command pipeline, allows you to capture the output of the preceding command to a file or files, while still sending it on to standard output (stdout) for further processing via other commands in a pipeline, or to print it, etc.

This recipe shows how to implement simple tee-like functionality via a Python class. I do not aim to exactly replicate the functionality of the Unix tee, only something similar.

More details and sample output here:

https://jugad2.blogspot.in/2017/03/a-python-class-like-unix-tee-command.html

[xtopdf] Publish Delimiter-Separated Values (DSV data) to PDF (Python)

2016-12-17T19:08:33-08:00

Python recipe 580736 by Vasudev Ram (commandline, csv, data, files, formats, pdf, pdf_generation, python, tsv, utilities, xtopdf).

This recipe shows how to publish delimiter-separated values (a commonly used tabular data format) to PDF, using the xtopdf toolkit for PDF creation. It lets the user specify the delimiter via one of two command-line options - an ASCII code or an ASCII character. As Unix filters tend to do, it can operate either on standard input or on input filenames given as command-line arguments. In the case of multiple inputs via files, each input goes to a separate PDF output file.

A simple text file pager in Python (Python)

2017-02-10T21:34:45-08:00

Python recipe 580755 by Vasudev Ram (command, commandline, pagination, paging, python, text, utilities, windows).

This recipe shows how to create a simple text file pager in Python. It allows you to view text content a page at a time (with a user-definable number of lines per page). Like standard Unix utilities, it can either take a text file name as a command-line argument, or can read the text from its standard input, which can be redirected to come from a file, or to come from a pipe. The recipe is for Windows only, though, since it uses the msvcrt.getch() function, which is Windows-specific. However, the recipe can be modified to work on Unix by using things like tty, curses, termios, cbreak, etc.

More details here:

https://jugad2.blogspot.in/2017/02/tp-simple-text-pager-in-python.html

Batch conversion of text files to PDF with fileinput and xtopdf (Python)

2016-11-07T20:28:01-08:00

Python recipe 580715 by Vasudev Ram (batch, batchmode, conversion, files, pdf, pdfwriter, python, text, text_processing, utilities, xtopdf).

This recipe shows how to do a batch conversion of the content of multiple text files into a single PDF file, with a) an automatic page break after the content of each text file (in the PDF output), b) page numbering, and c) a header and footer on each page.

It uses the fileinput module (part of the Python standard library), and xtopdf, a Python library for conversion of other formats to PDF.

xtopdf is available here: https://bitbucket.org/vasudevram/xtopdf

and a guide to installing and using xtopdf is here:

http://jugad2.blogspot.in/2012/07/guide-to-installing-and-using-xtopdf.html

Here is a sample run of the program:

python BTTP123.pdf text1.txt text2.txt text3.txt

This will read the content from the three text files specified and write it into the PDF file specified, neatly formatted.

Show OS error codes and messages from the os.errno module (Python)

2017-03-01T17:18:23-08:00

Python recipe 580759 by Vasudev Ram (commandline, introspection, libraries, python, unix, utilities, windows).

This recipe is a simple Python introspection utility that displays the defined OS error codes and messages (that Python knows about) from the os.errno module. It works for both Python 2 and Python 3. For each kind of OS error defined in Python, it will display a serial number, the error code, and the corresponding error name, and English error message. E.g. the first few lines of its output are shown below:

$ py -2 os_errno_info.py

Showing error codes and names

from the os.errno module:

Python sys.version: 2.7.12

Number of error codes: 86

Idx Code Name Message

0 1 EPERM Operation not permitted

1 2 ENOENT No such file or directory

2 3 ESRCH No such process

3 4 EINTR Interrupted function call

4 5 EIO Input/output error

More information, full output and other details are available here:

https://jugad2.blogspot.in/2017/03/show-error-numbers-and-codes-from.html

A utility like Unix seq (command-line), in Python (Python)

2017-01-08T17:48:57-08:00

Python recipe 580744 by Vasudev Ram (bash, command, commandline, linux, script, seq, sequence, shell, unix, utilities, utility).

This recipe shows how to create a utility like Unix seq (command-line), in Python. seq is described here:

https://en.wikipedia.org/wiki/Seq_(Unix)

but briefly, it is a command-line utility that takes 1 to 3 arguments (some being optional), the start, stop and step, and prints numbers from the start value to the stop value, on standard output. So seq has many uses in bigger commands or scripts; a common category of use is to quickly generate multiple filenames or other strings that contain numbers in them, for exhaustive testing, load testing or other purposes. A similar command called jot is found on some Unix systems.

This recipe does not try to be exactly the same in functionality as seq. It has some differences. However the core functionality of generating integer sequences is the same (but without steps other than 1 for the range).

More details and sample output are here:

https://jugad2.blogspot.in/2017/01/an-unix-seq-like-utility-in-python.html

The code is below.

A command-line musical alarm clock (Python)

2016-12-30T19:06:32-08:00

Python recipe 580739 by Vasudev Ram (alarm, audio, clock, multimedia, music, playsound, python, time, utilities, utility).

This is a simple musical alarm clock in Python. You pass a command-line argument specifying the time in minutes after which the alarm should go off. When that time arrives, it plays a musical sound.

Trap KeyboardInterrupt and EOFError for graceful program termination (Python)

2016-11-13T20:17:03-08:00

Python recipe 580718 by Vasudev Ram (ascii, error, exception, handler, shutdown, terminate, utilities, utility).

This recipe shows how to trap the KeyboardInterrupt and EOFError Python exceptions so that they do not crash your program. As a vehicle to show this, it uses a small Python utility that shows the ASCII code for any ASCII character you type.

Simple directory list command with filename wildcard support (Python)

2016-12-02T20:52:56-08:00

Python recipe 580724 by Vasudev Ram (commandline, directory, file, filesystem, python, utilities).

This recipe shows a simple directory listing program. It can accept multiple command-line arguments specifying filenames. These filenames can include wildcard characters like * (asterisk) and ? (question mark), as is common in OS command shells like bash (Unix) and CMD (Windows). Tested on Windows but should work on Unix too, since it uses no OS-specific functions, or rather, it does use them, but that happens under the hood, within the libraries used.

Process Delimiter-Separated Values data with Python (Python)

2016-11-24T23:57:35-08:00

Python recipe 580722 by Vasudev Ram (command, commandline, data, dsv, file, python, utilities, utility).

This recipe shows how to read and process delimiter-separated values (DSV) data with a Python command-line program. It provides two ways of specifying the delimiter character, by an ASCII character or an ASCII code, which makes it more flexible than allowing only a character. It allows the DSV data to be specified as one or more filenames on the command line, or given via the standard input of the program.

Image Resizer (Python)

2016-05-22T16:45:52-07:00

Python recipe 580663 by FB36 (image, images, utilities, utility). Revision 2.

Image resizer/converter command-line utility.

Unix-like split command in Python (simple version) (Python)

2016-03-14T22:35:05-07:00

Python recipe 580620 by Vasudev Ram (commandline, linux, python, shell, split, splitting, unix, utilities, utility, windows).

This recipe shows how to create a simple version of the Unix split command in Python. The split command splits an input file into multiple smaller files, the size of each of which is specified by a command-line argument giving the number of lines per file. This is useful for multiple purposes, such as editing large files in pieces, backing up files to small capacity storage devices, sending files across the network, etc.

File comparison utility in Python (Python)

2016-03-26T18:31:11-07:00

Python recipe 580631 by Vasudev Ram (commandline, comparison, file, files, linux, python, unix, utilities).

This is a recipe to compare any two files via a Python command-line program. It is like a basic version of the cmp command of Unix or the fc.exe (file compare) command of Windows.

Text ruler for console (record-oriented data processing utility) (Python)

2016-04-17T19:32:26-07:00

Python recipe 580647 by Vasudev Ram (commandline, python, rulers, unix, utilities, windows).

This recipe shows how to create a simple text-based ruler for your command-line console. It can help you find the position of your own program's output on the line, or to find the positions and lengths of fields in fixed- or variable-length records in a text file, fields in CSV files, etc.

FileSpec: Set it, forget it, reuse it (Python)

2016-03-08T05:49:16-08:00

Python recipe 580618 by Jack Trainor (filename, utilities).

Python provides good utilities for transforming filenames, but they are tedious to use and clutter up the source code.

FileSpec offers one-stop shopping to convert a file path to every component you might want to know, reuse, or transform.

A UNIX-like "which" command for Python (Python)

2015-03-20T19:23:45-07:00

Python recipe 579035 by Vasudev Ram (bash, commandline, commands, linux, shell, unix, utilities, which).

UNIX users are familiar with the which command. Given an argument called name, it checks the system PATH environment variable, to see whether that name exists (as a file) in any of the directories specified in the PATH. (The directories in the PATH are colon-separated on UNIX and semicolon-separated on Windows.)

This recipe shows how to write a minimal which command in Python. It has been tested on Windows.

Shortcut Utility (Python)

2015-03-29T20:45:57-07:00

Python recipe 579041 by FB36 (desktop, directories, directory, file, files, tkinter, ui, utilities, utility).

I dislike filling my desktop with shortcut icons in Windows. This code enables creating shortcuts in a CSV file.

Create module dependency graph (Python)

2010-05-07T11:29:03-07:00

Python recipe 577222 by Noufal Ibrahim (dependecies, graphs, utilities).

The following snippet will dump the module dependencies in a format that can be interpreted by the dot program distributed along with graphviz. You can use it like below to see the dependency graph for the asynchat module for example. (the program is saved as grapher.py)

python grapher.py asynchat | dot -Tpng | display

A screenshot is available here http://twitpic.com/1lqnmh