How to convert a string to date? I have a .csv file with dates formatted as '2020-01-11T00:00:00.000-05:00'.  When I read the file in python, it recognizes it as an object.  How can I convert it to a date '2020-01-11' using python?
How do I parse an ISO 8601-formatted date? I need to parse  strings like "2008-09-03T20:56:35.450686Z" into Python's datetime type.  I have found  in the Python standard library, but it is not very convenient.  What is the best way to do this?
What is the most concise and efficient way to find out if a JavaScript array contains a value? This is the only way I know to do it: function contains(a, obj) {     for (var i = 0; i &lt; a.length; i++) {         if (a[i] === obj) {             return true;         }     }     return false; }  Is there a better and more concise way to accomplish this? Given two points (defined, for instance using nodes), I want to compute the distance between them.   Is there some build in functionality in tikz to do this? If not, how can it be done using the mathematical engine?   The application I have in mind is to draw an circular arc centered at (a) and passing through some second point (b), where only (a) and (b) are known. How to center an element horizontally and vertically Where to find structure of objects that I can access in PHP snippets added to different parts of UI? Prove the compactness of a set B We have $A=\left\lbrace 2019,1010,\ldots,(n+2018)/n,\ldots \right\rbrace$ and $B=A \cup \left\lbrace 1 \right\rbrace$  How can I show directly (that is, not using the compactness criterion in $\mathbb{R}$) that every open cover $G$ of $B$ admits a finite subcover?  moreover, I know that $A$ is not compact and I am aware that I would need a single example to prove it, any hint on how to find an open cover of $A$ that does not contain a finite subcover?  My first thought was to choose the set of all neighborhoods with radius r centered around each point of A but apparently this is wrong and I do not understand why. Is "a total of 10 payments" singular or plural? A total of 10 payments were made.   OR     A total of 10 payments was made.   Which is correct? Or can both be correct? Do film industries outside India use intervals/Intermission? I can't destroy blocks in Minecraft Creative Mode (singleplayer) Why are site stats graph for beta sites not available to public? Currently, on all beta sites, the current site stats is placed prominently on the front page, which is great for knowing how the site is currently doing.  However, it doesn't say anything about the trend of the numbers - whether the site is sailing or it is sinking compared to the last month. According to Madara Uchiha, our moderator on Anime &amp; Manga SE, . Disregarding data which are not already public, , I can't see any reason why we are not allowed access to graphical representation of public site statistics. In fact, there is already a third-party app that scraps the information from the home page and . Can we have a beautiful visualization on how our beta sites evolve over time, from pony to unicorn?   Images stolen borrowed from Bulbapedia How to make beveled 90 degree corners on a curve better? I know the title is a mouthful, but this is the problem: I made a curve with 90 degree corners, like so:  I then beveled it, and this was the result:  As you can imagine, this isn't very pretty. I'm looking for something like this:  How can I achieve this look? Why can't light escape from a classical black hole? Doubt on Rechargable LED Emergency bulb I have recently seen a  and I  was wondering how it is working.  In the event of a power failure, the LED bulb will turn ON automatically. That is, when the switch is ON and mains power goes off the bulb will detect that and turn ON. If the switch is OFF bulb will not turn ON. When mains are ON and the switch is ON the bulb will start recharging again.  It is just like a normal bulb. See the   My question is, how the bulb will detect the event of mains failure? Can somebody give me a hint on this? Writing function definition in header files in C++ I have a class which has many small functions. By small functions, I mean functions that doesn't do any processing but just return a literal value. Something like:  string Foo::method() const{     return "A"; }   I have created a header file "Foo.h" and source file "Foo.cpp". But since the function is very small, I am thinking about putting it in the header file itself. I have the following questions:   Is there any performance or other issues if I put these function definition in header file? I will have many functions like this. My understanding is when the compilation is done, compiler will expand the header file and place it where it is included. Is that correct? Is “of ” necessary in “all of ”? Listen to all your fans   Name all the states   vs      Listen to all of  your fans   Name all of  the states   What part of language is of  in these examples? Is it necessary or optional, correct or incorrect? I am having trouble with this problem from my latest homework.  Prove the arithmetic-geometric mean inequality. That is, for two positive real numbers $x,y$, we have $$ \sqrt{xy}≤ \frac{x+y}{2} .$$ Furthermore, equality occurs if and only if $x = y$.  Any and all help would be appreciated. I have latitude and longitude as 19.0649070739746 and 73.1308670043945 respectively.   In this case both coordinates are 13 decimal places long, but sometimes I also get coordinates which are 6 decimal places long.   Do fewer decimal points affect accuracy, and what does every digit after the decimal place signify? How did Groot manage to raise the axe of Thor when even Hulk failed? In Avengers Hulk tried to raise Thor's hammer and failed miserably. In Avengers: Infinity War, Groot raises Thor's new axe and holds it for a few seconds! Is the axe made of some other light material, or is Groot stronger than Hulk? How does one manually restart graphics drivers? I'm suffering from the dreaded . The problem is intermittent and can be "solved" by putting the computer to sleep or restarting it. I hope simply restarting the graphics drivers will remove the symptoms of the problem.  would seem to indicate that restarting the graphics drivers is possible in Windows 7. My question is: how? Question about the Euclidean ring definition I recently came across the following definition for a euclidean ring:  There exists a function $g:R\to\Bbb N_0$ with the following properties:  1.) $\forall x,y \in R$ with $ y \neq 0$ there exist $q,r \in R$ with $x = qy + r$ where $r=0$ or $g(r) &lt; g(y)$.  2.) $\forall x,y\in R\setminus\{0\}$ we have $g(xy)\ge g(x)$  What I don't understand, is the point of the second requirement. I have seen definitions where this is not a requirement. What does 2.) achieve?   Thanks very much A locally constant sheaf on a locally connected space is a covering space; Proof? As part of my hobby i'm learning about sheaves from Mac Lane and Moerdijk. I have a problem with Ch 2 Q 5, to the extent that i don't believe the claim to be proven is actually true, currently. Here is the question repeated:     A sheaf on a locally connected space $X$ is locally constant if each point $x \in X$ has a basis of open neighborhoods  $\mathcal{N}_x$ such that whenever $U,V \in \mathcal{N}_x$ with $U \subset V$, the restriction $\mathcal{F}V \rightarrow \mathcal{F}U$ is a bijection. Prove that $\mathcal{F}$ is locally constant iff the associated etale space over $X$ is a covering.   I don't have a problem (i think) showing the "covering" $\rightarrow$ "locally constant" direction of the implication. My problem is in the reverse direction. In fact, in the process of trying to solve this problem i think i have come up with a very simple counterexample.  Here's my attempt at a counterexample:  Let $X = \{a,b,c\}$ be  finite space with open subsets $\{\{\},\{a\},\{a,b\},\{a,b,c\}\}$. I claim this is hyper-connected and locally connected.  Let $\mathcal{F}$ be the sheaf with $\mathcal{F}(\{a,b,c\}) = \{q\}$, $\mathcal{F}(\{a,b\}) = \{r,s\}$, and $\mathcal{F}(\{a\}) = \{t\}$, where $r = q|_{\{a,b\}}$, and $t = q|_{\{a\}} = r|_{\{a\}} = s|_{\{a\}}$. I claim this defines a locally constant sheaf. Indeed we can have $\mathcal{N}_{a} = \{\{a\}\}$, $\mathcal{N}_{b} = \{\{a,b\}\}$, and $\mathcal{N}_c = \{\{a,b,c\}\}$.  Now we can calculate the corresponding etale space $p : E \rightarrow X$ as follows: $E = \{\dot{q}(a), \dot{q}(b), \dot{q}(c), \dot{s}(b)\}$, and has these four distinct elements since $\dot{q}(a) = \dot{r}(a) = \dot{s}(a) = \dot{t}(a)$, and $\dot{q}(b) = \dot{r}(b)$. The action of $p$ follows by construction.  However, $p$ does not appear to me to be a covering space. In particular, the only neighborhoods of $b \in X$ are $\{a,b\}$and $\{a,b,c\}$ and we have $p^{-1}(\{a,b\}) = \{\dot{q}(a),\dot{q}(b),\dot{s}(b)\}$ and this cannot be partitioned into homeomorphic images of $\{a,b\}$ because $2 \nmid 3$. Similarly, $p^{-1}(\{a,b,c\}) = \{\dot{q}(a), \dot{q}(b), \dot{q}(c), \dot{s}(b)\}$ and this cannot be partitioned into homeomorphic images of $\{a,b,c\}$ since $3 \nmid 4$.  So i think i have a locally constant sheaf on a locally connected space whose corresponding etale space is not a covering. What have i done wrong? I have seen the claim mentioned elsewhere so i'm convinced i'm wrong somewhere. Perhaps someone knows where a correct proof is published otherwise?