While the “underlying number” is the same, all numbering systems are just different ways of expressing the same number. It’s the way that you, me, and the rest of us humans are used to counting, for no reason more complicated than that we have 10 fingers.īut there are other numbering systems as well that are especially prevalent throughout the CPython source code. This range of numbers is expressed in decimal (base 10). In the discussion of ASCII above, you saw that each character maps to an integer in the range 0 through 127. Remove ads Covering All the Bases: Other Number Systems Here are the binary versions of 0 through 10 in decimal: You can also express each of these base-10 numbers with a sequence of bits (base 2). Our ASCII table from the previous section uses what you and I would just call numbers (0 through 127), but what are more precisely called numbers in base 10 (decimal). There are different ways of symbolically representing a bit that all mean the same thing: Now is a good time for a short refresher on the bit, the most fundamental unit of information that a computer knows.Ī bit is a signal that has only two possible states. The subtle difference is because of definition: str.isprintable() considers something printable if “all of its characters are considered printable in repr().” A Bit of a Refresher This disagrees slightly with another method for testing whether a character is considered printable, namely str.isprintable(), which will tell you that none of are considered printable. Note: string.printable includes all of string.whitespace. Characters are segmented into different ranges within the ASCII table: Each single character has a corresponding code point, which you can think of as just an integer. The various categories outlined represent groups of characters. Don’t worry if you’re shaky on the concept of bits, because we’ll get to them shortly. Each character can be encoded to a unique sequence of bits. So what is a more formal definition of a character encoding?Īt a very high level, it’s a way of translating characters (such as letters, punctuation, symbols, whitespace, and control characters) to integers and ultimately to bits.
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