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Determine if variable is defined in Python [duplicate]

...ime? This is not always obvious because (1) the variable could be conditionally set, and (2) the variable could be conditionally deleted. I'm looking for something like defined() in Perl or isset() in PHP or defined? in Ruby. ...
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Are there benefits of passing by pointer over passing by reference in C++?

...ect", then use a pointer instead of a reference. Also, passing by pointer allows you to explicitly see at the call site whether the object is passed by value or by reference: // Is mySprite passed by value or by reference? You can't tell // without looking at the definition of func() func(mySpri...
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How to print a groupby object

...like a bug to me. I created an issue. But a groupby operation doesn't actually return a DataFrame sorted by group. The .head() method is a little misleading here -- it's just a convenience feature to let you re-examine the object (in this case, df) that you grouped. The result of groupby is separat...
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When to use Comparable and Comparator

... | Comparable | Comparator ._______________________________________________________________________________ Is used to allow Collections.sort to work | yes | yes Can compare multiple fields | yes ...
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How can I get the current language in Django?

...t: Returns None if translations are temporarily deactivated (by deactivate_all() or when None is passed to override()). Before Django 1.8, get_language() always returned LANGUAGE_CODE when translations were deactivated. – Pieter Jan 3 '17 at 13:11 ...
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Using reflect, how do you set the value of a struct field?

...rue if the value's address can be obtained with Addr. Such values are called addressable. A value is addressable if it is an element of a slice, an element of an addressable array, a field of an addressable struct, or the result of dereferencing a pointer. If CanAddr returns false, c...
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Implementing IDisposable correctly

...uld have any unmanaged resources to be freed you should include Finalizer calling Dispose(false), that will allow GC to call Finalizer when doing garbage collection (in case Dispose was not called yet) and properly free unmanaged resources. – mariozski May 17 '...
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What are the differences between double-dot “..” and triple-dot “…” in Git diff commit ranges?

...ion of the difference between .. (dot-dot) and ... (dot-dot-dot) is essentially the same as in manojlds's answer. The command git diff typically¹ only shows you the difference between the states of the tree between exactly two points in the commit graph. The .. and ... notations in git diff have t...
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How to send a correct authorization header for basic authentication

... This doesn't answer the question at all. Passing it as a url is not a header. – jemiloii Jan 29 '15 at 19:06 5 ...
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How do I reference a javascript object property with a hyphen in it?

Using this script to make a style object of all the inherited etc styles. 11 Answers ...