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Articles by SaiKrishna Tavva
Page 4 of 8
How does the destructor method __del__() work in Python?
The __del__() method in Python is a special method called a destructor. It is automatically called when an object is about to be destroyed or garbage collected, allowing you to perform cleanup operations before the object is removed from memory. Basic Syntax The destructor method follows this syntax − class MyClass: def __init__(self, name): self.name = name print(f"Object {self.name} created") def __del__(self): ...
Read MoreHow do I get an ISO 8601 date in string format in Python?
The ISO 8601 standard defines an internationally recognised format for representing dates and times. ISO 8601 is a date and time format that helps remove different forms of the day, date, and time conventions worldwide. In this article, we will discuss several methods to get an ISO 8601 date in string format in Python. ISO 8601 Date Format In Python, ISO 8601 date is represented as "YYYY-MM-DDTHH:MM:SS.mmmmmm" format. For example, August 25, 2023, is represented as 2023-08-25T14:35:45.123456. YYYY: Year (four digits) MM: Month (from 1-12) ...
Read MoreHow to compare calendar.timegm() vs. time.mktime() in Python?
In Python, the mktime() function (from the time module) assumes that the passed tuple is in local time, while the calendar.timegm() (from the calendar module) assumes it's in GMT/UTC. Depending on the interpretation, the tuple represents a different time, so both functions return different values (seconds since the epoch are UTC-based). The difference between the values should be equal to the time zone offset of your local time zone. Understanding time.mktime() in Local Time Context The Python time.mktime() method converts the object form of local time into seconds since the epoch (January 1, 1970, 00:00:00 UTC). ...
Read MoreHow to convert timestamp string to datetime object in Python?
In many real-world applications, timestamps are used to represent dates and times, but they are not human-readable. To make them understandable or use them in various datetime manipulations, it's essential to convert them into Python's datetime object. Python's datetime module provides multiple functions to convert timestamps to datetime objects. Below are the various methods to accomplish this task ? Using datetime.fromtimestamp() Function Using datetime.fromtimestamp() & strftime() Using datetime.strptime() Function Parsing Mixed Text Using strptime() Function Using datetime.fromtimestamp() Function ...
Read MoreHow do I get time of a Python program\'s execution?
Python provides different ways to measure the execution time of a script or specific code segments. The most common approaches use functions from the time module like time.time() and time.process_time(), or the dedicated timeit module for precise measurements. Here are the main methods to measure execution time in Python: Using time.time() Function Using time.process_time() Function Using timeit Module Using time.time() Function The time.time() function returns the current time as a floating-point number representing seconds since the Unix epoch (January 1, 1970). This ...
Read MoreHow to measure time with high-precision in Python?
Python provides various modules, such as time, datetime, and timeit, to measure time with high accuracy. These modules offer high-resolution clocks to measure time intervals with precision needed for performance analysis and benchmarking. The following are several methods used to measure time with high precision in Python. Using time.time() Method Using time.perf_counter() Function Using timeit.default_timer() Using time.time() Method for Simple Timing The time.time() method returns the current time in seconds since the epoch as a floating-point number. The epoch is system-dependent, but ...
Read MoreWhich one is more accurate in between time.clock() vs. time.time()?
Two commonly used functions from the Python time module are time.time() and time.clock(). Each function provides a different purpose and returns different values depending on the platform (Windows vs. Unix). In Python 3.8, time.clock() was removed, so time.perf_counter() or time.process_time() are generally preferred over the older time.clock() for specific CPU time measurements. The time.clock() was designed for measuring process CPU time, while time.time() measures wall-clock time. time.time() is more accurate for measuring overall elapsed time (the duration of time that has passed between two specific points in time). Measuring Elapsed Time with time.time() The time.time() function ...
Read MoreWhat are negated character classes that are used in Python regular expressions?
While working with Python regex, if we want to match everything except certain characters, then we can use negated character classes by placing a caret (^) as the first character inside square brackets. The pattern [^abdfgh] will match any character not in that set. What is a Negated Character Class? A character class like [abc] matches any single character that is 'a', 'b', or 'c'. But if we use a ^ symbol at the beginning, like [^abc], it will match any character except 'a', 'b', or 'c'. This allows us to exclude certain characters from the match quickly. ...
Read MoreHow does nested character class subtraction work in Python?
Nested character class subtraction in Python's regular expressions allows us to define complex character sets by removing specific characters from an existing character class using the '-' operator within square brackets. Python's built-in re module doesn't support nested character class subtraction directly. Instead, we need to use the third-party regex module, which can be installed using pip install regex. Syntax The basic syntax for character class subtraction is ? [character_set--[characters_to_exclude]] For example, [0-9--[4-6]] matches digits 0-9 but excludes 4, 5, and 6, effectively matching 0, 1, 2, 3, 7, 8, and 9. ...
Read MoreHow to match whitespace but not newlines using Python regular expressions?
In Python, regular expressions (regex) provide powerful tools to search and manipulate strings. When you need to match whitespace characters like spaces and tabs but exclude newline characters, you can use specific regex patterns with Python's re module. The following methods demonstrate how to match whitespace but not newlines using Python regular expressions ? Using re.sub() Method Using re.findall() Method Using Character Classes Using Positive Lookahead Using re.sub() Method The re.sub() method efficiently replaces whitespace characters (excluding newlines) ...
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