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What is 'Pattern Matching' in functional languages?
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143
Understanding pattern matching requires explaining three parts:
Algebraic data types.
What p...
Run command on the Ansible host
...If you want to run an entire play on the Ansible host, then specify hosts: 127.0.0.1 and connection:local in the play, for example:
- name: a play that runs entirely on the ansible host
hosts: 127.0.0.1
connection: local
tasks:
- name: check out a git repository
git: repo=git://foosball...
Share Large, Read-Only Numpy Array Between Multiprocessing Processes
... = n/num
shared = sharedmem.empty(n)
shared[:] = numpy.random.rand(1, n)[0]
print "values are %s" % shared
processes = [Process(target=do_work, args=(shared, i*width)) for i in xrange(num)]
for p in processes:
p.start()
for p in processes:
p.join()
print...
Format decimal for percentage values?
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answered Nov 24 '09 at 15:56
Michael HarenMichael Haren
93.9k3939 gold badges157157 silver badges198198 bronze badges
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How to reuse an ostringstream?
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157
I've used a sequence of clear and str in the past:
// clear, because eof or other bits may be...
Difference between var_dump,var_export & print_r
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194
var_dump is for debugging purposes. var_dump always prints the result.
// var_dump(array('', ...
How do I select elements of an array given condition?
Suppose I have a numpy array x = [5, 2, 3, 1, 4, 5] , y = ['f', 'o', 'o', 'b', 'a', 'r'] . I want to select the elements in y corresponding to elements in x that are greater than 1 and less than 5.
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Can PostgreSQL index array columns?
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184
Yes you can index an array, but you have to use the array operators and the GIN-index type.
E...
Is there any way to prevent input type=“number” getting negative values?
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16 Answers
16
Active
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Operation on every pair of element in a list
... module. It does exactly what you describe.
import itertools
my_list = [1,2,3,4]
for pair in itertools.product(my_list, repeat=2):
foo(*pair)
This is equivalent to:
my_list = [1,2,3,4]
for x in my_list:
for y in my_list:
foo(x, y)
Edit: There are two very similar functions as...