What I learned today

You may have seen this question, center a div, or whatever, in interviews or other places. I am sure there are other approaches than I am sharing here, but I found these two cool ideas from multiple places (see refs at the end). These are not my original ideas so I will be sure to share where I learned these from:   Using display:flex  Make sure you know how flex works, but to do centering with flex, it's ridiculously simple: div .container { display : flex ; justify-content : center ; /* horizontal alignment */ align-items : center ; /* vertical alignment */ flex-direction : column ; /* since we are doing a vertical column */ padding : 1rem 3rem ; /* not related to centering */ }  Now everything inside <div class="container"> </div> will be centered in both directions! Using display:grid  You are so going to thank for me this one, you are welcome. This one is so simple it does not even need an explanation does it?   div .conta...

 When do you use em and when do you use rem? If you have ever asked this, you are like me :) So welcome. Basically, to save you time here it is: - If you want your font-size relative to the container's font-size, use em - If you want your font-size relative to the 'root' (or html) element's font-size, use rem! If you just stop reading now that might be sufficient, but if you are more curious, go on. Example companion codepen: https://codepen.io/binodpanta/pen/RwLWRra Basically your page should ideally always have a default font-size specified for the root, such as  :root { font-size: 1em; } This typically becomes 16px default for the base font size. Now, if you use rems in your elements' styles you get a consistent scaling wrt this number! so if you do div.someclass { font-size: 0.5rem; } you are going to always get a nice scaled font size regardless of screen size. So all your fonts will scale relatively throughout the app!  If you had used 0.5em, your calculated ...

Sometimes you need a function that already 'captures' some information you don't want to repeat when calling it. For example, logging may require you to pass in a lot of contextual information for each call. Instead you can capture the common/unchanging contextual information in a function (using its clsoosure) then call the resulting function with less args (only those that are changing in each call site)   class AClass:   def __init__(self):     self.make_log_msg = lambda m: f"a={self.a}, b={self.b}, message={m}"  def do_something(self):     doStuff();     logger.info(self.make_log_msg('test message')) In the absence of the make_log_msg() function you would need to pass all of a,b,c into every logging function call as in self.make_log_msg(self.a, self.b, message) .  This is possible because make_log_msg returns a function (lambda function in this case) that already captures the values self.a and self.b in its closure at the t...