Interprocess Communication Python
How do I pass a string into subprocess.Popen (using the stdin argument)?
Let $F$ be a field and $f: \mathbb{Z} \to F$ be a ring epimorphism. Last year I hired someone to do some work for our website but accidentally lost the PSD files since then. It's a fairly basic concept but I am fairly inexperienced with using masks.  How can I create the black circular gradient area as shown in this image below? I need to get as close as possible where it matches existing images on the site, why I am hoping its not too hard.  Thank you! Could it be that Goldbach conjecture is undecidable? Changing background color to transparent in GeoServer? How to set the background color to transparent. I want use style which describe in *.sld file for all my photo with tif format. How to do that? What can I do to prevent passport stamps being put on blank pages? I'm running low on blank passport pages which are sometimes needed for full page visas such as those issued by Armenia, India, and Vietnam.  When I crossed the border into Turkey the other day I got my visa-on-arrival and stamp, but instead of putting it on a partly used page, which I have many, the guy at customs and immigration put them on a previously blank page. Now I have one fewer!  What can I do to prevent or at least reduce the chances of this happening?  It's worth remembering that there's likely to be a language barrier and it's always best to be ultra-nice to these border officials.  Has anybody heard of any trick such as sticking bit of paper in your passport, either blank, or looking a bit like visas? I have noticed that nobody ever stamps a page that has a remnant of something once stapled in there in Japan. There is a kind of stub that had its major part torn off along a perforation. Might I be able to emulate this somehow or would that even be worse making the blank pages invalid for full page visas due to having holes from staples? I know some things can get very picky when it comes to customs and immigration. How to Give Credit for An Answer in the Comments I asked a question on SO and someone gave me the answer as a comment to the question. Subsequently, someone else gave the same answer as an answer.  I would like to give credit to the poster who made the comment. Is there any way to do that?   Being new to the site, my only thought would be to contact the commenter and tell him to post an answer if he/she wants credit. A type-I superconductor can expel almost all magnetic flux (below some critical value $H_c$) from its interior when superconducting. Light as we know is an electromagnetic wave. So what would happen if we shine a light deep into a type-I superconductor? Suppose the magnetic field of the light is significantly lower than $H_c$.  And what about type-II superconductors? Book identification: technologically-enhanced man (1970s/80s YA) "IllegalFormatConversionException: d != java.lang.String" when padding number with 0s? Pluralizing Numbered Items If low-cost index funds are considered the best investment, why are there so many high-cost, managed funds? The general consensus is that the single best indicator of a fund's future performance is the its expense ratio . If you look for more than 5 minutes online you discover the  approach to investing; the , etc. It looks like the less you pay for a fund (and therefore the less it's managed), the better it does in the long run.  So why is it that in peoples' 401(k)s there are so many high-cost actively managed funds? Furthermore, why are there so many high-cost actively managed funds in the first place? Shouldn't the market reflect the fact that actively-managed funds typically don't beat the index they benchmark to and and react by purging itself of these crappy funds? When is a biased estimator preferable to unbiased one? ST_Length (GEOM, true) for calculating distances in Geographic Reference System HP Easy Scan - "HP Scanner 3" will damage your computer Capacitor with different charges on each plate I am confused as to whether/how capacitance changes when each plate has a different charge.  For example, consider a coaxial cable and put $20Q$ on the outer cable, and $-Q$ on the inner. Or how about concentric spheres, grounding either the inner or the outer? Our company would like to understand the effects:   If we have single table with Primary Key Identity column, int primary key IDENTITY(1,1),  and the Application is conducting multi-threading parallel processing, trying to conducts 1000s of simultaneous inserts on one table.   Would the identity primary key column fail, with a primary key violation in any way, for example: processors are trying to input the same identity number?  Or was SQL designed to be successful even in multithreading parallel insert?  Note: IDENTITY_INSERT is OFF How to select the most recent set of dated records from a mysql table Allow Documentation in other Stack Exchange communities I'm a Salesforce developer and would love Documentation to be available in other Stack Exchange communities. The reason is  a lot of Salesforce developers get help, especially newer ones like myself. The developer forums and documentation on  is mediocre. It would be nice to allow users to create their own and give pack on The formula for a one sample t-test, as given by  is  $t = \dfrac{\bar{x} - \mu_0}{s\big/\sqrt{n}}$  However, in this equation, if the sample standard deviation, $s$, is zero, $t$ will be undefined. Is there any reasonable way to get a $t$ value in this case? Are $(x^3)^{1/3} $ and $\sqrt{x^2}$ monomials?    In mathematics, a  is, roughly speaking, a polynomial which has only one term. Two different definitions of a monomial may be encountered:  For the first definition, a monomial, also called power product, is a product of powers of variables with nonnegative integer exponents, or, in other words, a product of variables, possibly with repetitions.   For the second definition, a monomial is a monomial in the first sense multiplied by a nonzero constant, called the coefficient of the monomial.