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Why can't I use a list as a dict key in python?
...uality. Many would - understandably - expect that you can use any list [1, 2] to get the same key, where you'd have to keep around exactly the same list object. But lookup by value breaks as soon as a list used as key is modified, and for lookup by identity requires you to keep around exactly the sa...
Linq style “For Each” [duplicate]
...
288
Using the ToList() extension method is your best option:
someValues.ToList().ForEach(x => ...
How do I use the conditional operator (? :) in Ruby?
...t for precedence issues. Both are expressions.
Examples:
puts (if 1 then 2 else 3 end) # => 2
puts 1 ? 2 : 3 # => 2
x = if 1 then 2 else 3 end
puts x # => 2
Note that in the first case parenthesis are required (otherwise Ruby is confused because i...
What does |= (ior) do in Python?
...e examples below.
Sets
For example, the union of two assigned sets s1 and s2 share the following equivalent expressions:
>>> s1 = s1 | s12 # 1
>>> s1 |= s2 # 2
>>> s1.__ior__(s2) ...
In Python, how do I iterate over a dictionary in sorted key order?
...
Haven't tested this very extensively, but works in Python 2.5.2.
>>> d = {"x":2, "h":15, "a":2222}
>>> it = iter(sorted(d.iteritems()))
>>> it.next()
('a', 2222)
>>> it.next()
('h', 15)
>>> it.next()
('x', 2)
>>>
If you are us...
How can I obtain the element-wise logical NOT of a pandas Series?
...
274
To invert a boolean Series, use ~s:
In [7]: s = pd.Series([True, True, False, True])
In [8]:...
Datatype for storing ip address in SQL Server
... IPv4 is binary(4), since that is what it actually is (no, not even an INT32/INT(4), the numeric textual form that we all know and love (255.255.255.255) being just the display conversion of its binary content).
If you do it this way, you will want functions to convert to and from the textual-displ...
How to search for occurrences of more than one space between words in a line
...
[ ]{2,}
SPACE (2 or more)
You could also check that before and after those spaces words follow. (not other whitespace like tabs or new lines)
\w[ ]{2,}\w
the same, but you can also pick (capture) only the spaces for tasks...
How to return dictionary keys as a list in Python?
In Python 2.7 , I could get dictionary keys , values , or items as a list:
8 Answers
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How to get overall CPU usage (e.g. 57%) on Linux [closed]
...
Take a look at cat /proc/stat
grep 'cpu ' /proc/stat | awk '{usage=($2+$4)*100/($2+$4+$5)} END {print usage "%"}'
EDIT please read comments before copy-paste this or using this for any serious work. This was not tested nor used, it's an idea for people who do not want to install a utility or...