How can I use an attribute of the instance as a default argument for a method? [duplicate]

You can’t really define this as the default value, since the default value is evaluated when the method is defined which is before any instances exist. The usual pattern is to do something like this instead: class C: def __init__(self, format): self.format = format def process(self, formatting=None): if formatting is None: formatting = self.format print(formatting) … Read more

How can I target a specific column or row in a CSS grid layout?

To style an arbitrary row, you could use a wrapper element with its display set to contents. See the code snippet below: .grid-container { display: grid; grid-template-columns: repeat(5, 1fr); grid-gap: 2px; } .grid-item { border: 1px solid black; padding: 5px; } .grid-row-wrapper { display: contents; } .grid-row-wrapper > .grid-item { background: skyblue; } <div class=”grid-container”> … Read more

What is output buffering in PHP?

Output Buffering for Web Developers, a Beginner’s Guide: Without output buffering (the default), your HTML is sent to the browser in pieces as PHP processes through your script. With output buffering, your HTML is stored in a variable and sent to the browser as one piece at the end of your script. Advantages of output … Read more

Detect if the internet connection is offline?

Almost all major browsers now support the window.navigator.onLine property, and the corresponding online and offline window events. Run the following code snippet to test it: console.log(‘Initially ‘ + (window.navigator.onLine ? ‘on’ : ‘off’) + ‘line’); window.addEventListener(‘online’, () => console.log(‘Became online’)); window.addEventListener(‘offline’, () => console.log(‘Became offline’)); document.getElementById(‘statusCheck’).addEventListener(‘click’, () => console.log(‘window.navigator.onLine is ‘ + window.navigator.onLine)); <button id=”statusCheck”>Click … Read more

Pass a PHP variable to a JavaScript variable

Expanding on someone else’s answer: <script> var myvar = <?= json_encode($myVarValue, JSON_UNESCAPED_UNICODE); ?>; </script> Using json_encode() requires: PHP 5.2.0 or greater $myVarValue encoded as UTF-8 (or US-ASCII, of course) Since UTF-8 supports full Unicode, it should be safe to convert on the fly. Please note that if you use this in html attributes like onclick, … Read more

Why do I get “AttributeError: NoneType object has no attribute” using Tkinter? Where did the None value come from?

The grid, pack and place functions of the Entry object and of all other widgets returns None. In python when you do a().b(), the result of the expression is whatever b() returns, therefore Entry(…).grid(…) will return None. You should split that on to two lines like this: entryBox = Entry(root, width=60) entryBox.grid(row=2, column=1, sticky=W) That … Read more