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Skip to content Best IDE and Code Editor for Python Language RECENT Python Requests Module: What it is and How to use it What is Tkinter in Python | Tkinter Tutorial in Details Pillow Python: What it is and How to use it? Complete SQL Tutorial with Examples Python Tutorial for Beginners | Python Basics List, Set, Tuple, and Dictionary in Python Thread Synchronization Mechanisms in Python Applicati

Updated Sep 18, 2007 | Fredrik Lundh ElementTree provides limited support for XPath expressions. The goal is to support a small subset of the abbreviated syntax; a full XPath engine is outside the scope of the core library. The 1.2 release supports simple element location paths. In its simplest form, a location path is one or more tag names, separated by slashes (/). You can also use an asterisk (

Here’s a simple django view which creates a PIL image on the fly, and returns it as a PNG image: from django.utils.httpwrappers import HttpResponse from PIL import Image import random INK = "red", "blue", "green", "yellow" def image(request): # ... create/load image here ... image = Image.new("RGB", (800, 600), random.choice(INK)) # serialize to HTTP response response = HttpResponse(mimetype="imag

December 7, 2005 | Fredrik Lundh Python’s getattr function is used to fetch an attribute from an object, using a string object instead of an identifier to identify the attribute. In other words, the following two statements are equivalent: value = obj.attribute value = getattr(obj, "attribute")If the attribute exists, the corresponding value is returned. If the attribute does not exist, you get an

If you try to stop a CPython program using Control-C, the interpreter throws a KeyboardInterrupt exception. Unfortunately, this is an ordinary exception, and is, like all other exceptions, caught by a “catch-all” try-except statement. try: # do something except: # you'll end up here if something goes wrong, # or if the user presses control-c For example, if your program contains code like the foll

What is a color gradient? Color gradients, or color transitions, is a gradual blending from one color to another between same color tone (from light blue to navy blue), colors of two different tones (from blue to yellow), or even between more than two colors (from blue to purple to red to orange). It can be of tow types, LINEAR, in which color originates in a linear line or RADIAL, where color rad

This article discusses how to synchronize access to shared resources and otherwise coordinate execution of threads. Synchronizing Access to Shared Resources One important issue when using threads is to avoid conflicts when more than one thread needs to access a single variable or other resource. If you’re not careful, overlapping accesses or modifications from multiple threads may cause all kinds

Also see the PIL FAQ (dead link). Why does PIL say “The _imaging C module is not installed”? The PIL library consists of two main parts: a number of Python modules, usually stored in a PIL subdirectory, and a binary extension module called _imaging. Depending on platform and version, the latter is stored in a file named _imaging.pyd, _imaging.dll or _imaging.so (or some variation thereof). If Pyth

What is Python? Python is one of the most popular general-purpose programming language which is used for almost all types of projects ranging from web development to mobile app development. Even though the Python Language is among us for the last 30 years, it grew tremendously in popularity in the last few years due to the advancement of Data Science. Why learn Python? Python is one of the popular

In this post, we have explained in detail how to deal with XML files in Python. We will also see some of the complex terms of ElementTree module. What are XML files? Extensible Markup Language (XML) is a file format that is used for the serialization of data, that is, storing, transmitting, and reconstructing arbitrary data, in a format that is both human-readable and machine-readable. As a markup

July 11, 2002 | Fredrik Lundh This note describes how Python calculates hash values for some internal data types. Strings Strings (both 8-bit and Unicode) use the following hash function: class string: def __hash__(self): if not self: return 0 # empty value = ord(self[0]) << 7 for char in self: value = c_mul(1000003, value) ^ ord(char) value = value ^ len(self) if value == -1: value = -2 return va

Fredrik Lundh | August 2007 Since I’m running effbot.org on a shared server with limited memory for long-running processes, I’m quite interested in keeping track of my Django application’s resource usage. As part of this, I wanted an easy way to see what the memcached server I’m using for caching is up to, and came up with a a simple Django view that grabs the current status from the server. Here’

February 19, 2003 | Fredrik Lundh Some Python distributions add information to the Windows registry when installed. This information is used by certain tools, such as the win32all installer and Windows installers generated by the distutils (dead link) package. If you’re using an unregistered Python environment, you’ll usually end up with an empty list of alternatives on the installer’s “Select Pyt

Updated December 2, 2000 | Fredrik Lundh The Console module provides a simple console interface, which provides cursor-addressable text output, plus support for keyboard and mouse input. The Console module is currently only available for Windows 95, 98, NT, and 2000. It probably works under Windows XP, but it hasn’t been tested on that platform. Software (including precompiled binaries) and docume

Fredrik Lundh | August 2006 The ElementSoup module is a (slightly experimental) wrapper for Leonard Richardson’s robust BeautifulSoup HTML parser, which turns the BeautifulSoup data structure into an element tree. The resulting combo is similar to ElementTidy, but a lot less picky. And therefore, a lot more practical. Which is good. Code (latest versions):ElementSoup.py [history] BeautifulSoup.py

In this post, we have explained in detail how to deal with XML files in Python. We will also see some of the complex terms of ElementTree module. What are XML files?Extensible Markup Language (XML) is a file format that is used for the serialization of data, that is, storing, transmitting, and reconstructing arbitrary data, in a format that is both human-readable and machine-readable. As a markup

What is Python?Python is one of the most popular general-purpose programming language which is used for almost all types of projects ranging from web development to mobile app development. Even though the Python Language is among us for the last 30 years, it grew tremendously in popularity in the last few years due to the advancement of Data Science. Why learn Python?Python is one of the popular p

Learn to Code: Python Tutorial | Tkinter | SQL | Pillow PIL | Python, JavaScript, C, C++, Data Science, Data Analytics

Learn to Code: Python Tutorial | Tkinter | SQL | Pillow PIL | Python, JavaScript, C, C++, Data Science, Data Analytics