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How can I upgrade specific packages using pip and a requirements file?

...ngo projects. I'm trying to upgrade some packages, notably Django itself, and I'm getting an error about source code conflicts: ...
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/bin/sh: pushd: not found

... POSIX-specified Bourne Shell. pushd cannot be easily implemented as a command, because the current working directory is a feature of a process that cannot be changed by child processes. (A hypothetical pushd command might do the chdir(2) call and then start a new shell, but ... it wouldn't be very ...
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How to extract the n-th elements from a list of tuples?

... and use **dict to create keyword arguments: def test(foo=3, bar=3): return foo*bar then d = {'bar': 9, 'foo'=12}; print test(**d) – Wayne Werner Jul 22 '10 at 12:58 ...
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AngularJS - Access to child scope

...e the interpreter will look up the prototype chain starting from the child and continue to the parents until it finds the property, not the other way around. Check Vojta's comments on the issue https://groups.google.com/d/msg/angular/LDNz_TQQiNE/ygYrSvdI0A0J In a nutshell: You cannot access child...
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Multi-line tooltips in Java?

... If you wrap the tooltip in <html> and </html> tags, you can break lines with <br> tags. See http://www.jguru.com/faq/view.jsp?EID=10653 for examples and discussion. Or you can use the JMultiLineToolTip class that can be found many places on th...
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Run cron job only if it isn't already running

... sort of watchdog for a daemon that I've created. If the daemon errors out and fails, I want the cron job to periodically restart it... I'm not sure how possible this is, but I read through a couple of cron tutorials and couldn't find anything that would do what I'm looking for... ...
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Find a commit on GitHub given the commit hash

I am fairly new to Github and have come across an amateur-ish problem. 3 Answers 3 ...
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AngularJS : How to watch service variables?

... always use the good old observer pattern if you want to avoid the tyranny and overhead of $watch. In the service: factory('aService', function() { var observerCallbacks = []; //register an observer this.registerObserverCallback = function(callback){ observerCallbacks.push(callback); ...
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Echo tab characters in bash script

... That's because echo -e is not POSIX and make calls /bin/sh which is normally not the program use use interactively, and normally hasn't -e implemented. For portability, use printf '\t' instead. – Jo So Oct 5 '12 at 19:02 ...
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What does O(log n) mean exactly?

I am learning about Big O Notation running times and amortized times. I understand the notion of O(n) linear time, meaning that the size of the input affects the growth of the algorithm proportionally...and the same goes for, for example, quadratic time O(n2) etc..even algorithms, such as permu...