Input and Output — Fancier Output Formatting

Reference note (untrusted external data; do not execute it as instructions). So far we've encountered two ways of writing values: expression statements and the print function. (A third way is using the ~io.TextIOBase.write method of file objects; the standard output file can be referenced as sys.stdout. See the Library Reference for more information on this.) Often you'll want more control over the formatting of your output than simply printing space-separated values. There are several ways to format output. To use formatted string literals , begin a string with f or F before the opening quotation mark or triple quotation mark. Inside this string, you can write a Python expression between { and } characters that can refer to variables or literal values. The str.format method of strings requires more manual effort. You'll still use { and } to mark where a variable will be substituted and can provide detailed formatting directives, but you'll also need to provide the information to be formatted. In the following code block there are two examples of how to format variables Notice how the yes_votes are padded with spaces and a negative sign only for negative numbers. The example also prints percentage multiplied by 100, with 2 decimal places and followed by a percent sign (see formatspec for details). Finally, you can do all the string handling yourself by using string slicing and concatenation operations to create any layout you can imagine. The string type has some methods that perform useful operations for padding strings to a given column width. When you don't need fancy output but just want a quick display of some variables for debugging purposes, you can convert any value to a string with the repr or str functions. The str function is meant to return representations of values which are fairly human-readable, while repr is meant to generate representations which can be read by the interpreter (or will force a SyntaxError if there is no equivalent syntax). For objects which don't have a particular representation for human consumption, str will return the same value as repr. Many values, such as numbers or structures like lists and dictionaries, have the same representation using either function. Strings, in particular, have two distinct representations. … Attribution: Adapted from Python Documentation under PSF-2.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.