probelm in printing a list in python
Understanding slice notation
I've got a DVD that I've burnt from an MSDN ISO. I'm not entirely sure if its Windows 7 64bit or 32bit.   How can I be sure? I have an Excel file that has a bunch of VBA and macro code in it.  When I open the file in Excel I can choose not to 'enable' them - so the values in the fields all stay as they were during the last save.  I need to manipulate the values as they were last saved - so I don't want the macros (which look at the current date and update values accordingly) to run.  When I open it via our dot net code:   Dim oxlRep As Excel.Application Dim oWBRep As Excel.Workbook Dim oSheetRep As Excel.Worksheet Dim oRngRep As Excel.Range oxlRep.Open(path)   the vb code runs - throwing off the values.  I've been looking for a way to open it without macros, or in 'secure' mode where the macros aren't run.  If I simply double click the file and don't choose to enable macros the values are all there as I want them.    Usually we run this code within the month that the files are created, so we haven't seen this problem in the 3 or 4 years that it has been working.  Now I need to go back to some of the old files and run some archival code...    Anyone have a suggestion? This is a canonical question that will hopefully encompass all of the questions we get asking us to determine what year a bicycle was manufactured (how old is my bike, how old is my frame, etc.). Each "answer" should address a different way to determine the manufacturing year of a bicycle. To some extent, these will also help you narrow down the model as well as it will tell you what distinguishing features to look at.  The span of answers would include things such as:      Skiptooth cranks Cartridge bottom brackets (BB30/90 etc) Elliptical chainring Quick releases versus contemporary through-axles How the steerer attaches to the fork (quill vs. threadless)  Braking system (especially with mountain bikes: v-brake, direct pull, etc.)   Shifting ramps and pins on cassettes/sprockets and chainrings (versus flat sprockets) Frame material (e.g., shift from tubular steel to use of CF and hydroformed aluminium)  Frame tubing type (e.g. Reynolds 531 tubing introduced around 1934, still used today; Reynolds 501 tubing introduced around 1983). So a frame with an original 501 decal can't be from the 70', 531 decal doesn't help as much because of the range of years produced. Also, see Decals.   *Decals: style/design, amount, placement, color, etc. can help not only determine models, but also year of manufacture. Many changed decal design for the same model bike often yearly, with special/limited editions even more specific. This applies only if decals are original or have been replaced with the identical design. Tubing decals (Reynolds, Columbus, etc.) also changed designs for same tubing made in different years, although the changes aren't made as often, and manufacturers didn't always put tubing Brand decals on every model. Earlier bikes tended to have less fancy, less colorful, less quantity of decals.   Headbadges: most early bikes had actual "badges", often quite detailed and fancy, made of metal, then plastic, and finally just using decals on the headtube. Most bikes lost their metal badges in the 60's and early 70's, although some brands still have actual badges to this day, but in general a real badge indicates an earlier model bike. Dropout style (including the later inclusion of lawyers lips) Presence or absence of CPSC reflectors (USA only) Manufacturing method (shift from lugs to TIG welding, for example)  Number of gears (shift from 2x5 ten-speed to 3x8, 2x9, 1x11, etc.)  Inspection of lug design: pantographs, cut-out, stampings, custom brazing/filing, chrome, fork crow n sweep, etc. Frame/Fork Braze-ons. Race bikes tended have less braze-ons the earlier the year of manufacture. Most 60's racers and earlier had few or none with cable guides/stops, shifters, bidons, etc. being clamp-on. By the 80's if it was clamp-on, it was a sign of very cheap models and most frames had braze-ons for all cables, with multiple bottle and accessory bosses depending on style and use.   and so forth. Please edit this question if you have an answer that isn't in the index above.   A couple of caveats:   A previous owner could have replaced or upgraded components on a bicycle, so this guide only applies to original equipment There is a delay between the introduction of a technology (such as indexed shifting) and when manufacturers start selling products that use it. Low-end manufacturers may continue using technology that is severely outdated (such as one-piece cranks, freewheels, or quill stems) because it is cheaper to do so. A number of bikes are built in a Retro style, but with modern components.  Dutch bikes, trendy coffee cruisers, and beach cruisers may be modern but appear to be 1950s styling.  These tend to have modern rims and brakes as a giveaway.     Note that bicycles.stackexchange does not do valuations of bicycles. How much your bicycle is worth depends on the location of the buyer and seller, how much the buyer wants the bike, etc. etc. etc. How does the Rectified Linear Unit (ReLU) activation function produce non-linear interaction of its inputs? When used as an activation function in deep neural networks The ReLU function outperforms other non-linear functions like tanh or sigmoid . In my understanding the whole purpose of an activation function is to let the weighted inputs to a neuron interact non-linearly. For example, when using $sin(z)$ as the activation, the output of a two input neuron would be:  $$ sin(w_0+w_1*x_1+w_2*x_2) $$   which would approximate the function  $$  (w_0+w_1*x_1+w_2*x_2) - {(w_0+w_1*x_1+w_2*x_2)^3 \over 6} + {(w_0+w_1*x_1+w_2*x_2)^5 \over 120} $$  and contain all kinds of combinations of different powers of the features  $x_1$ and $x_2$.   Although the ReLU is also technically a non-linear function, I don't see how it can produce non-linear terms like the $sin(), tanh()$ and other activations do.  Edit: Although my question is similar to , I'd like to know how even a cascade of ReLUs are able to approximate such non-linear terms. I've been writing in English for many years, but there are certain recurring issues that come up in my writing, which I can't seem to resolve permanently. Primarily I have a problem with punctuation. In my native language, commas are very commonly used. One would place a comma to separate any portion of the sentence that serves a specific grammatical role. At least, this is the case according to the rules I was taught in school. I can see when I write in English that there are extraneous commas, but I can't always figure out which ones, and why. When dependent clauses require commas, when do they allow them, and when are they definitely incorrect? Why are there two tensions on my free body diagram? A man sits on a platform attached to a pulley and pulls himself up as shown (ignore the angle of the rope - it should be vertical). Apparently, the man/platform object has a force of 2T pulling it up. Why is it not just T?  Much appreciated! Can I prepay a Credit Card to make a Large Purchase greater than my credit limit? I want to make a large purchase at a retail store to the sum of $10,000 but the credit limit on my card is set at $2000.  If I send $10K to my credit card will the purchase be allowed to go through?  Not sure if the credit limit is a hard limit or not?  I don't want to be left embarrassed if my card is declined in the store lol.  I called my bank but the answer they gave wasn't too convincing. It was kind of "Errr yes i think its OK!"  Does any one know first hand? How to cook fall-off-the-bone beef spare ribs in oven or on stove top? All,  I would like to cook spare ribs to a fall-off-the-bone consistency.  I don't have access to a grill.  I know how to do that with pork shoulders (dry rubbed, then uncovered in the oven at low heat for 6-8hrs), but spare ribs are a different type of animal.  They are individually smaller pieces (my ribs are sawed in chunks), and they are fairly fatty, with a big bone.  What should I do?  Should I pan-sear them first, do I need some liquid in the dish?  Should I cover them?  Thanks,  JDelage How to find out what's accessing a particular hard drive on Windows? I'm reading Galois Theory by Steven H. Weintraub (second edition), and finding that I'm at least somewhat short on the prerequisites. However the following proof looks wrong to me - am I misunderstanding something, or is it actually an incorrect proof?  Lemma 2.2.3. Let $F$ be a field and $R$ an integral domain that is a finite-dimensional $F$-vector space. Then $R$ is a field. Proof. We need to show that any nonzero $r \in R$ has an inverse. Consider $\{1, r, r^2, \cdots\}$. This is an infinite set of elements of $R$, and by hypothesis $R$ is finite dimensional as an $F$-vector space, so this set is linearly dependent. Hence $\sum_{i=0}^n{c_i r^i} = 0$ for some $n$ and some $c_i \in F$ not all zero.  It then goes on to show, given the above, that we can derive an inverse for $r$. However, if I consider examples like $r = 2 \in Q[\sqrt{2}]$, $r = \sqrt{2} \in Q[\sqrt{2}]$ or $r = 2 \in Q[X]/{&lt;X^2&gt;}$, the set $\{1, r, r^2, ...\}$ doesn't look linearly dependent to me. I do believe the lemma is true (and might even be able to prove it), but this does not look like a correct proof to me. Am I missing something? [Edit] Well yes, I am. Somehow I had managed to discount the possibility of any $c_i$ being negative, despite repeatedly looking at each fragment of the quoted text in an attempt to find what I might be misunderstanding. Rounding up to next power of 2 I want to write a function that returns the nearest next power of 2 number. For example if my input is 789, the output should be 1024. Is there any way of achieving this without using any loops but just using some bitwise operators? cardinality of the set of $ \varphi: \mathbb N \to \mathbb N$ such that $\varphi$ is an increasing sequence I know that the set of functions $ f:\mathbb N \to \mathbb N$ is uncountable, but what if we consider only $f$ such that $f$ is increasing? I want to know if this set is countable D: and also the case of bijective and increasing (clearly if the firstone holds then this too). I think that it could be possible that it's countable I'm trying to create record Type selection screen in LWC, but getting this error  afterRender threw an error in 'c:createContact' [Cannot read property 'recordTypeInfos' of undefined]  HTML:  &lt;template&gt;     &lt;lightning-combobox name="recordType" label="Record Type" placeholder="Choose Status"                         value={value}                          options={recordTypeId}&gt;      &lt;/lightning-combobox&gt; &lt;/template&gt;   JS:  import { LightningElement, track, wire, api } from 'lwc'; import { getObjectInfo } from 'lightning/uiObjectInfoApi'; import CONTACT_OBJECT from '@salesforce/schema/Contact';  export default class CreateContact extends LightningElement {      @track statusOptions;     @track value;     @api objectApiName;      @track objectInfo;      @wire(getObjectInfo, { objectApiName: CONTACT_OBJECT,})     objectInfo;       get recordTypeId() {         // Returns a map of record type Ids          console.log(this.objectInfo);         const rtis = this.objectInfo.data.recordTypeInfos;         return rtis;     }  } From injective map to continuous map How to set up passwordless SSH access for root user I need to configure a machine so software installation can be automated remotely via SSH. Following , I was able to setup SSH keys so my user can access the machine without a password, but I still need to manually enter my password when I use sudo, which obviously an automated process shouldn't have to do.  Although my /etc/ssh/sshd_config has PermitRootLogin yes, I can't seem to be able to log in as root, presumably because it's not a "real" account with a separate password.  How do I configure SSH keys, so a process can remotely log in as root on Ubuntu? I'm hoping someone can give me a nudge in the right direction...     Let $F$ be a finite field, and let $f(x)$ be a nonconstant polynomial whose derivative is the zero polynomial.  Prove that $f$ cannot be irreducible over $F$.   I've got that every root of $f$ is a multiple root and that for $F=\mathbb{F}_{p^r}$, the exponent of every term of $f$ is a multiple of $p$. I am just starting into calculus and I have a question about the following statement I encountered while learning about definite integrals:  $$\sum_{k=1}^n k^2 = \frac{n(n+1)(2n+1)}{6}$$  I really have no idea why this statement is true. Can someone please explain why this is true and if possible show how to arrive at one given the other? What's the best way to generate a tag cloud from an array using h1 through h6 for sizing? Extraneous solution from substituting in equations I came across this example of how you could end up with an extraneous solution but I was wondering how it arose. We have the equation: $$x^2+x+1=0 $$ Since x=0 does not satisfy the equation, you can divide by x on both sides which yields: $$x+1+\frac{1}{x}=0$$ which is equivalent to our first equation. From our first eqution we can conclude that: $$-x^2=x+1$$ We now substitute that into the second equation to get:$$x^2=\frac{1}{x}$$ which results in $$x^3=1$$ which is equivalent to our previous equation since x cannot be 0. However, one solution from our last equation is x=1, which is not a solution to our original equation. I have a vague idea that it may have to do with the fact that you get a cubic equation and you began with a quadratic, and that steps imply the following and not vice versa, but can you provide a very detailed answer as to why it arises? Can you please provide more examples? prove that $\mathbb{Q}^n$is dense subset of $\mathbb{R^n}$ Prove that $\mathbb{Q}^n$is dense subset of $\mathbb{R^n}$ using the fact that $\mathbb{Q}$ is dense subset  of $\mathbb{R}$  I know that $\mathbb{Q}$ is dense subset  of $\mathbb{R}$ That is, between any two real numbers, there exists a rational number  then how to prove that $\mathbb{Q}^n$is dense subset of $\mathbb{R^n}$