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This recipe shows how to generate a PDF cheat sheet, that contains a table for conversion of the numbers 0 to 255 (the numbers that can fit in one byte) between binary, octal, decimal and hexadecimal representations. The table has four columns, one for each of those bases, and 256 rows, for the numbers 0 to 255.

TO use the table, you can look for a number, say in decimal, in the Dec(imal) column (or use the search function of your PDF viewer), then when you find it in some row, just look at the other 3 columns in that row, to find the value of that number in binary, octal and hexadecimal. And use the same procedure if starting with a number in any of the other three bases.

Python, 44 lines
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44``` ```# number_systems.py: from __future__ import print_function from PDFWriter import PDFWriter import sys ''' A program to generate a table of numbers from 0 to 255, in 4 numbering systems: - binary - octal - decimal - hexadecimal Author: Vasudev Ram Copyright 2016 Vasudev Ram Web site: https://vasudevram.github.io Blog: http://jugad2.blogspot.com Product store on Gumroad: https://gumroad.com/vasudevram ''' def print_and_write(s, pw): print(s) pw.writeLine(s) sa, lsa = sys.argv, len(sys.argv) if lsa == 1: sys.stderr.write("Usage: {} out_filename.pdf\n".format(sa)) sys.exit(1) with PDFWriter(sa) as pw: pw.setFont('Courier', 12) pw.setHeader('*** Number table: 0 to 255 in bases 2, 8, 10, 16 ***') pw.setFooter('*** By xtopdf: https://google.com/search?q=xtopdf ***') b = "Bin"; o = "Oct"; d = "Dec"; h = "Hex" header = "{b:>10}{o:>10}{d:>10}{h:>10}".format(b=b, o=o, d=d, h=h) for i in range(256): if i % 16 == 0: print_and_write(header, pw) print_and_write("{b:>10}{o:>10}{d:>10}{h:>10}".format( \ b=bin(i), o=oct(i), d=str(i), h=hex(i)), pw) print_and_write(header, pw) ```

Apart from a few standard library modules, the utility requires the xtopdf toolkit for PDF creation, which was created by me. You can get it from the Bitbucket site for xtopdf:

https://bitbucket.com/vasudevram/xtopdf

http://slides.com/vasudevram/xtopdf

There is more discussion and sample output here: Created by Vasudev Ram on Mon, 10 Oct 2016 (BSD)