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Convert to binary and keep leading zeros in Python
I'm trying to convert an integer to binary using the bin() function in Python. However, it always removes the leading zeros, which I actually need, such that the result is always 8-bit:
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Cleaner way to update nested structures
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Huet's Zipper provides convenient traversal and 'mutation' of an immutable data structure. Scalaz provides Zippers for Stream (scalaz.Zipper), and Tree (scalaz.TreeLoc). It turns out that the structure of the zipper is automatically derivable from the original data structure, in a manner that re...
Understanding the map function
Apply function to every item of iterable and return a list of the results. If additional iterable arguments are passed, function must take that many arguments and is applied to the items from all iterables in parallel.
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How can I convert a dictionary into a list of tuples?
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>>> d = { 'a': 1, 'b': 2, 'c': 3 }
>>> d.items()
[('a', 1), ('c', 3), ('b', 2)]
>>> [(v, k) for k, v in d.iteritems()]
[(1, 'a'), (3, 'c'), (2, 'b')]
It's not in the order you want, but dicts don't have any specific order an...
Is it good practice to use the xor operator for boolean checks? [closed]
...ke the exclusive or , ^ , operator when it makes sense in the context of boolean checks because of its conciseness. I much prefer to write
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Covariance, Invariance and Contravariance explained in plain English?
Today, I read some articles about Covariance, Contravariance (and Invariance) in Java. I read the English and German Wikipedia article, and some other blog posts and articles from IBM.
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A monad is just a monoid in the category of endofunctors, what's the problem?
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That particular phrasing is by James Iry, from his highly entertaining Brief, Incomplete and Mostly Wrong History of Programming Languages, in which he fictionally attributes it to Philip Wadler.
The original quote is from Saunders Mac Lane in Categorie...
Shortcuts in Objective-C to concatenate NSStrings
Are there any shortcuts to ( stringByAppendingString: ) string concatenation in Objective-C, or shortcuts for working with NSString in general?
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Reference — What does this symbol mean in PHP?
This is a collection of questions that come up every now and then about syntax in PHP. This is also a Community Wiki, so everyone is invited to participate in maintaining this list.
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When is “i += x” different from “i = i + x” in Python?
...he standard notation of i = i + . Is there a case in which i += 1 would be different from i = i + 1 ?
3 Answers
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