Popular recipes tagged "meta:license=bsd" but not "python"

Convert wildcard text files to PDF with xtopdf (e.g. report*.txt) (Python)

2016-12-06T20:37:30-08:00

Python recipe 580727 by Vasudev Ram (conversion, files, globbing, patterns, pdf, pdfwriter, pdf_generation, text_processing, wildcard, xtopdf).

This recipe shows how to convert all text files matching a filename wildcard to PDF, using the xtopdf PDF creation toolkit. For example, if you specify report.txt as the wildcard, all files in the current directory that match report.txt, will be converted to PDF, each in a separate PDF file. The original text files are not changed.

Here is a guide to installing and using xtopdf:

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

More details on running the program, and sample output, are available here:

http://jugad2.blogspot.in/2016/12/xtopdf-wildcard-text-files-to-pdf-with.html

Classifying characters using nested conditional expressions (Python)

2017-04-27T21:26:00-07:00

Python recipe 580792 by Vasudev Ram (characters, classification, conditional_expressions, expressions, join, lambda, map).

Python has a feature called conditional expressions, similar to C's ternary operator. For example:

print n, 'is odd' if n % 2 == 1 else 'is even'

Here, the conditional expression is this part of the print statement above:

'is odd' if n % 2 == 1 else 'is even'

This expression evaluates to 'is odd' if the condition after the if keyword is True, and evaluates to 'is even' otherwise.

The Python Language Reference section for conditional expressions shows that they can be nested. This recipe shows that we can use nested conditional expressions (within a return statement in a user-defined function) to classify characters into lowercase letters, uppercase letters, or neither.

It also shows how to do the same task using map, lambda and string.join, again with a nested conditional expression, but without using return or a user-defined function.

Read CSV with D and write it to PDF with Python (Python)

2016-10-26T17:49:00-07:00

Python recipe 580710 by Vasudev Ram (conversion, csv, data, files, formats, pdf, pdf_generation, xtopdf).

This recipe shows how to read data from a CSV file with a D program and write that data to a PDF file with a Python program - all in a single command-line invocation (after writing the individual programs, of course).

It requires the xtopdf toolkit, which you can get from:

https://bitbucket.org/vasudevram/xtopdf

Instructions for installing xtopdf:

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

xtopdf in turn requires the open source version of the ReportLab toolkit, which you can get from:

http://www.reportlab.com/ftp (http://www.reportlab.com/ftp/reportlab-1.21.1.tar.gz)

It also requires the DMD compiler to compile the D program - this was the version used:

DMD32 D Compiler v2.071.2

A simple Unix shell utility to save cleaned-up man pages as text (Bash)

2017-03-25T14:12:25-07:00

Bash recipe 580766 by Vasudev Ram (bash, documentation, man, script, shell, utilities, utility).

It's a shell script that lets you save the man pages for one or more Unix commands, system calls or other topics, to text files, after cleaning up the man command output to remove formatting meant for emphasis, printing, etc.

More information here:

https://jugad2.blogspot.in/2017/03/m-unix-shell-utility-to-save-cleaned-up.html

Number of bits needed to store an integer, and its binary representation (Python)

2017-03-12T23:10:48-07:00

Python recipe 580762 by Vasudev Ram (binary, formats, integers, numbers, representation, type).

This recipe shows how to find, via Python code, the number of bits needed to store an integer, and how to generate its binary representation. It does this for integers from 0 to 256.

More details and full output here:

https://jugad2.blogspot.in/2017/03/find-number-of-bits-needed-to-store.html

Easily create a Python REPL in Python (Python)

2016-10-31T21:53:30-07:00

Python recipe 580712 by Vasudev Ram (code_module, dynamic, evaluation, read_eval_print_loop, repl).

This recipe shows how to easily create a Python REPL (Read-Eval-Print Loop) in Python itself. This can allow the user to interact with a running Python program, including typing in Python statements at the REPL prompt, defining functions, using and changing variables that were set before the interaction started, and those variables modified during the interaction, will persist in the memory of the program, for any use, even after the interaction is over, as long as the program continues to run.

Two quick functions for object introspection (Python)

2017-01-14T22:35:17-08:00

Python recipe 580747 by Vasudev Ram (attributes, debugging, functions, introspection, methods, objects, reflection).

This recipe shows two quick-and-clean :) utility functions for introspection of Python objects. They are meant to be used while working interactively in the reular Python shell or in the IPython shell. Both of them display attributes of any given object passed as the argument. The first function displays all attributes. The second function only displays atttributes that do not begin and end with a double underscore, so as to filter out "dunder" methods a.k.a. "special" methods - like __len__, __str__, __repr__, etc. The first function - oa(o) , where o is some object - does the same as dir(o), but is useful - in IPython - because, dir(o) output will scroll off the screen if the output is long, since it prints the attributes vertically, one per line, while oa(o) prints them horizontally, so has less chance of the output scrolling off, and the output also occupies fewer lines on the screen, so is easier to scan quickly. The second function - oar(o) - is like oa(o), but filters out attribute names that begin and end with a dunder. So it is useful in both IPython and Python.

More information and outputs here:

https://jugad2.blogspot.in/2017/01/two-simple-python-object-introspection.html

Quick-and-dirty Windows drive detector (Python)

2016-09-20T17:46:37-07:00

Python recipe 580699 by Vasudev Ram (drives, sysadmin, system_programming, utility, windows).

This is a quick-and-dirty Python script to detect the currently available drives on your Windows PC.

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.

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.

Convert JSON to PDF with Python and xtopdf (Python)

2014-12-10T18:02:14-08:00

Python recipe 578979 by Vasudev Ram (json, pdfwriter, sys).

This recipe show the basic steps needed to convert JSON input to PDF output, using Python and xtopdf, a PDF creation toolkit. xtopdf is itself written in Pytho, and uses the ReportLab toolkit internally.

We set up some needed values, such as the output PDF file name, the font name and size, the header and footer, and the input lines for the body of the PDF output; all these values are passed in JSON format (in a single dictionary) to a function that uses those values to generate a PDF file with the desired content.

The code is intentionally kept simple so as to require the least amount of code needed to demonstrate the techniques involved. But it can be generalized or extended to more complex situations.

Get names and types of all attributes of a Python module (Python)

2016-10-06T17:21:42-07:00

Python recipe 580705 by Vasudev Ram (documentation, introspection, modules, reflection, type).

This recipe shows how to get the names and types of all the attributes of a Python module. This can be useful when exploring new modules (either built-in or third-party), because attributes are mostly a) data elements or b) functions or methods, and for either of those, you would like to know the type of the attribute, so that, if it is a data element, you can print it, and if it is a function or method, you can print its docstring to get brief help on its arguments, processsing and outputs or return values, as a way of learning how to use it.

The code for the recipe includes an example call to it, at the end of the code. Note that you first have to import the modules that you want to introspect in this way.

Functional D plus Python pipeline to generate PDF (Text)

2016-09-22T15:32:17-07:00

Text recipe 580701 by Vasudev Ram (pdfwriter, pdf_generation, pipe, pipeline, xtopdf).

This recipe is a command pipeline. The first component of the pipeline is a D language program that makes use of simple functional programming and template / generic programming features of D, to transform some input into the desired output. Both input and output are text. The D program writes the output to standard output, which is then read by a Python program that reads that as input via standard input, and converts it to PDF.

The many uses of randomness - Part 2 (Python)

2016-07-17T17:26:47-07:00

Python recipe 580690 by Vasudev Ram (random, random_number, simulation, testing).

This is the second recipe in the series about the uses of randomness in Python. The first recipe is here:

https://code.activestate.com/recipes/580674-the-many-uses-of-randomness-part-1/?in=user-4173351

This second recipe shows some uses of random numbers to generate random characters and random strings of various categories, and some purposes for which these generated strings can be used in testing.

A Pythonic ratio that equals pi (Python)

2016-06-26T20:38:24-07:00

Python recipe 580686 by Vasudev Ram .

This shows how to find two integer values whose ratio approximates the mathematical constant, pi, somewhat accurately.

Dependency resolution (Python)

2016-04-14T12:58:40-07:00

Python recipe 580642 by Mike 'Fuzzy' Partin (compare, dependency, sort, sorting).

This recipe shows how to take a list of objects, each with their own list of dependencies, and resolve them to proper order. It includes some poor mans circular dependency detection (very poor mans).

Printing an ASCII table to PDF (Python)

2015-04-02T18:38:04-07:00

Python recipe 579043 by Vasudev Ram (ascii, pdf, pdf_generation, xtopdf).

This recipe shows how to print part of an ASCII table to PDF. It shows it for the first 32 ASCII characters, the control characters, i.e. the characters with ASCII codes 0 to 31. The same logic can be extended to print the remaining ASCII characters, either upto code 127 or 255, depending on your definition of ASCII, and also on whether your PDF font supports printing all those characters.

data_dump.py, like the Unix od (octal dump) command (Python)

2015-11-01T12:43:38-08:00

Python recipe 579120 by Vasudev Ram (data, dump, hexadecimal, linux, octal, od, representation, unix, utility, windows).

This recipe implements a simple data dump tool, roughly like the od command of Unix, which stands for octal dump (though od can also dump data in hex and other formats). This tool dumps data in character and hex formats, in this version. This is data_dump.py version 1.

Publish SQLite data to PDF using named tuples (Python)

2015-02-24T22:08:11-08:00

Python recipe 579027 by Vasudev Ram (conversion, pdf, pdfwriter, sql, sqlite, sqlite3, xtopdf).

This recipe shows how to publish SQLite data to PDF, using named tuples from the collections module of Python, the sqlite3 library, and the xtopdf library for PDF generation.

Use PrettyTable and xtopdf to create PDF tables with borders, alignment and padding (Python)

2015-01-24T21:21:27-08:00

Python recipe 579012 by Vasudev Ram (data, pdf, prettytable, string, tabular, xtopdf).

This recipe shows how to create tabular data in PDF format, supporting neat borders, and alignment and padding of columns, using the Python libraries called PrettyTable and xtopdf.