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How to index into a dictionary?
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Dictionaries are unordered in Python versions up to and including Python 3.6. If you do not care about the order of the entries and want to access the keys or values by index anyway, you can use d.keys()[i] and d.values()[i] or d.items()[i]. (Note that these methods create a list of all keys, va...
How do I concatenate or merge arrays in Swift?
...arrays with +, building a new array
let c = a + b
print(c) // [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]
or append one array to the other with += (or append):
a += b
// Or:
a.append(contentsOf: b) // Swift 3
a.appendContentsOf(b) // Swift 2
a.extend(b) // Swift 1.2
print(a) // [1.0, 2.0,...
How to check if variable is string with python 2 and 3 compatibility
I'm aware that I can use: isinstance(x, str) in python-3.x but I need to check if something is a string in python-2.x as well. Will isinstance(x, str) work as expected in python-2.x? Or will I need to check the version and use isinstance(x, basestr) ?
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C#位运算符（C#按位与、按位或 等） - 更多技术 - 清泛网 - 专注C/C++及内核技术
...如：10010001（二进制）&11110000等于10010000（二进制）。
3、位逻辑或运算
位逻辑或运算将两个运算对象按位进行或运算。或运算的规则是：1或1等1，1或0等于1，
0或0等于0。比如10010001（二进制）| 11110000（二进制）等于11110001...
What are the mathematical/computational principles behind this game?
...nd you have the question:
Can we have a geometry with just 2 points? With 3 points? With 4? With 7?
There are still open questions regarding this problem but we do know this:
If there are geometries with Q points, then Q = n^2 + n + 1 and n is called the order of the geometry.
There are n+1 poin...
When should iteritems() be used instead of items()?
... of iteritems() in all places? Why was iteritems() removed from Python 3? Seems like a terrific and useful method. What's the reasoning behind it?
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Understanding the map function
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edited Jun 3 '15 at 13:16
myildirim
1,67822 gold badges1414 silver badges2424 bronze badges
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Replace values in list using Python [duplicate]
...n-place if you want, but it doesn't actually save time:
items = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
for index, item in enumerate(items):
if not (item % 2):
items[index] = None
Here are (Python 3.6.3) timings demonstrating the non-timesave:
In [1]: %%timeit
...: items = [0, 1, 2, 3,...
Could not find com.google.android.gms:play-services:3.1.59 3.2.25 4.0.30 4.1.32 4.2.40 4.2.42 4.3.23
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edited Dec 3 '15 at 1:20
CJBS
12.4k55 gold badges6868 silver badges119119 bronze badges
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