Server Side Programming Articles - Page 2352 of 2646

In this article, we will talk about creating iterators for efficient looping in Python functions. An iterator is something that helps you go through all the items one by one, like going through pages of a book one page at a time. In Python, we can use lists, tuples, dictionaries, and sets as iterators. So we will explore Python functions that generate iterators for efficient looping. Creating Iterators with Functions Python provides different ways to create iterators using functions. So let us see some examples of creating iterators for efficient looping in Python functions - Using Generator Functions Using ... Read More

This article will explain how decimal fixed-point and floating-point arithmetic work in Python, which is useful for performing accurate calculations in various applications. Numbers in Python can be stored in two ways: floating-point and decimal fixed-point. Floating-point numbers are fast but can sometimes be incorrect because of how computers store them. On the other hand, Decimal fixed-point numbers are more accurate and useful when working with precise calculations.  By the end of this article, you will understand how both types of numbers work, when to use them, and how to write programs using them. Floating-Point Arithmetic The following example will ... Read More

Purpose of linecache module in Python’s standard library is to facilitate random access to any text file, although this module is extensively used by Python’s traceback module to generate error trace stack. Further prettyprints of reading are held in a cache so that it saves time while reading lines repeatedly.The most important function in this module is getline() which reads a specified line number from given file. Following is the list of functions −getline(file, x)This function returns xth line from file. If not present it will return empty string. If the file is not present in current path, function ties ... Read More

Python’s built-in open() function opens one file in read/write mode and read/write operations on it. To perform processing on multiple files in a batch, one has to use fileinput module of Python’s standard library. This module provides a Fileinput class with functionality of iterating over files. The module also defines helper functions for the same purpose.Primary interface to this module is input() function. This function returns instance of Fileinput class.fileinput.input(files, inplace, mode)The files parameter is name of one or more files to be read one by one. Each file acts as a generator and using a for loop it can ... Read More

The pathlib module provides an object oriented approach to handling filesystem paths. The module also provides functionality appropriate for various operating systems. Classes defined in this module are of two types – pure path types and concrete path types. While pure paths can only perform purely computational operations, concrete paths are capable of doing I/O operations too.pathlib module defines following classes −Sr.No.Module & Description1PurePathThe base class for all other classes2Pathsubclassed from PurePath. This is a concrete class that represents filesystem path.3PosixPathPath subclass for non-Windows OS4WindowsPathPath subclass for Windows systems5PurePosixPathPurePath subclass for non-Windows systems6PureWindowsPathPurePath subclass for Windows systemsWhen instance of Path ... Read More

Python Object Persistence  The shelve module in Python's standard library is a simple yet effective tool for persistent data storage when using a relational database solution is not required. The shelf object defined in this module is a dictionary-like object persistently stored in a disk file. This creates a file similar to dbm database on UNIX-like systems. The only string data type can be used as a key in this special dictionary object, whereas any pickable object can serve as value. The shelve module defines three classes as follows − ... Read More

The usleep() function delays execution of the current script for few microseconds.Syntaxusleep(msec)Parametersmsec − The number of microseconds to delay the script.ReturnThe usleep() function returns nothing.Example Live DemoOutputThe following is the output.03:06:08 03:06:10 03:06:15

The unpack() function unpacks data from a binary string.Syntaxunpack(format, data)Parametersformat − The format to use. Here are the possible valuesa −NUL-padded stringA − SPACE-padded stringh − Hex string, low nibble firstH − Hex string, high nibble firstc − signed charC −unsigned chars − signed short (always 16 bit, machine byte order)S − unsigned short (always 16 bit, machine byte order)n − unsigned short (always 16 bit, big endian byte order)v − unsigned short (always 16 bit, little endian byte order)i − signed integer (machine dependent size and byte order)I − unsigned integer (machine dependent size and byte order)l − signed ... Read More

The uniqid() function generates a unique ID based on the current time in microseconds.Syntaxuniqid(prefix, more_entropy)Parametersprefix − The prefix to the unique ID.more_entropy − The more entropy at the end of the return value.ReturnThe uniqid() function returns unique identifiers as string.Example Live DemoOutputThe following is the output.5bfd5bd045faa

The time_sleep_until() function delays execution of the current script until the specified time. Syntax time_sleep_until(time) Parameters time − The time until execution will delay. Return The time_sleep_until() function returns true on success. Example The execution of the above script is now delayed for 15 seconds.