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Python: Tuples/dictionaries as keys, select, sort
...said, you should also consider namedtuple(). That way you could do this:
>>> from collections import namedtuple
>>> Fruit = namedtuple("Fruit", ["name", "color"])
>>> f = Fruit(name="banana", color="red")
>>> print f
Fruit(name='banana', color='red')
>>>...
How do I increase the capacity of the Eclipse output console?
...
Under Window > Preferences, go to the Run/Debug > Console section, then you should see an option "Limit console output." You can uncheck this or change the number in the "Console buffer size (characters)" text box below.
(This is in...
str performance in python
...s evaluated by the compiler and is equivalent to a constant at run-time.
>>> import dis
>>> dis.dis(lambda: str(100000))
8 0 LOAD_GLOBAL 0 (str)
3 LOAD_CONST 1 (100000)
6 CALL_FUNCTION 1
9 ...
How do I create an empty array/matrix in NumPy?
...as your data set will eventually be, and then add data to it row-by-row:
>>> import numpy
>>> a = numpy.zeros(shape=(5,2))
>>> a
array([[ 0., 0.],
[ 0., 0.],
[ 0., 0.],
[ 0., 0.],
[ 0., 0.]])
>>> a[0] = [1,2]
>>> a[1] = [2,3]
>>>...
How to get a random value from dictionary in python
...
If you don't want to use the random module, you can also try popitem():
>> d = {'a': 1, 'b': 5, 'c': 7}
>>> d.popitem()
('a', 1)
>>> d
{'c': 7, 'b': 5}
>>> d.popitem()
('c', 7)
Since the dict doesn't preserve order, by using popitem you get items in an arbitrary ...
Array to Hash Ruby
...
a = ["item 1", "item 2", "item 3", "item 4"]
h = Hash[*a] # => { "item 1" => "item 2", "item 3" => "item 4" }
That's it. The * is called the splat operator.
One caveat per @Mike Lewis (in the comments): "Be very careful with this. Ruby expands splats on the stack. If you do ...
Optimal way to concatenate/aggregate strings
...TITION grouping and ordering them as needed for the concatenation. The result is Partitioned CTE. We keep counts of rows in each partition to filter the results later.
Using recursive CTE (Concatenated) iterate through the row numbers (NameNumber column) adding Name values to FullName column.
Filter...
In Python, how do you convert a `datetime` object to seconds?
...timedelta object, which as of Python 2.7 has a total_seconds() function.
>>> (t-datetime.datetime(1970,1,1)).total_seconds()
1256083200.0
The starting date is usually specified in UTC, so for proper results the datetime you feed into this formula should be in UTC as well. If your datetim...
What is the purpose of the single underscore “_” variable in Python?
...reter stores the last expression value to the special variable called _.
>>> 10
10
>>> _
10
>>> _ * 3
30
The underscore _ is also used for ignoring the specific values. If you don’t need the specific values or the values are not used, just assign the values to und...
List of zeros in python [duplicate]
...er(n):
listofzeros = [0] * n
return listofzeros
sample output:
>>> zerolistmaker(4)
[0, 0, 0, 0]
>>> zerolistmaker(5)
[0, 0, 0, 0, 0]
>>> zerolistmaker(15)
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
>>>
...