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Repeat string to certain length

... that need to be // in Python 3? Or dropping the +1 and using an explicit call to a ceiling function would suffice. Also, a note: the string generated actually has an extra repetition when it divides evenly; the extra gets cut off by the splice. That confused me at first. – jpm...
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What's an elegant way to conditionally add a class to an HTML element in a view?

...sses where the boolean value evaluated to true. Sample Usage class_names(foo: true, bar: false, baz: some_truthy_variable) # => "foo baz" Other Use Cases This helper can be used within ERB tags or with Rails helpers such as link_to. <div class="<%= class_string(ok: @success) %>"&gt...
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How to use range-based for() loop with std::map?

... called structured bindings, which allows for the following: std::map< foo, bar > testing = { /*...blah...*/ }; for ( const auto& [ k, v ] : testing ) { std::cout << k << "=" << v << "\n"; } ...
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How do I check if a directory exists? “is_dir”, “file_exists” or both?

...post input and uses it as-is, plus makes 0777 dir, prolly not that safe at all ;P – sEver Aug 20 '13 at 16:45 2 ...
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Join strings with a delimiter only if strings are not null or empty

... .filter(Boolean) (which is the same as .filter(x => x)) removes all "falsy" values (nulls, undefineds, empty strings etc). If your definition of "empty" is different, then you'll have to provide it, for example: [...].filter(x => typeof x === 'string' && x.length > 0) wi...
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Rename multiple files by replacing a particular pattern in the filenames using a shell script [dupli

...ho "$f" | sed s/IMG/VACATION/)"; done In this example, I am assuming that all your image files contain the string IMG and you want to replace IMG with VACATION. The shell automatically evaluates *.jpg to all the matching files. The second argument of mv (the new name of the file) is the output of t...
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List goals/targets in GNU make that contain variables in their definition

...utput from make -pn (i.e. make --print-data-base --dry-run)? It prints out all the variables, rules, implicit rules and which commands will be run in laborious detail. share | improve this answer ...
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RESTfully design /login or /register resources?

...ounter. [...] [... H]andling [of GET requests] by the server is not technically limited in any way. Therefore, careless or deliberate programming can cause non-trivial changes on the server. This is discouraged, because it can cause problems for Web caching, search engines and other automated agents...
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How to tell git to ignore individual lines, i.e. gitignore for specific lines of code [duplicate]

...o be filtered: *.rb filter=gitignore, i.e. run filter named gitignore on all *.rb files Define the gitignore filter in your gitconfig: $ git config --global filter.gitignore.clean "sed '/#gitignore$/d'", i.e. delete these lines $ git config --global filter.gitignore.smudge cat, i.e. do nothing ...
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Define a lambda expression that raises an Exception

...ur goal is to avoid a def, this obviously doesn't cut it. It does, however allow you to conditionally raise exceptions, e.g.: y = lambda x: 2*x if x < 10 else raise_(Exception('foobar')) Alternatively you can raise an exception without defining a named function. All you need is a strong stom...