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Is there a way to pass optional parameters to a function?
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The Python 2 documentation, 7.6. Function definitions gives you a couple of ways to detect whether a caller supplied an optional parameter.
First, you can use special formal parameter syntax *. If the function definition has a formal p...
quick random row selection in Postgres
... myid FROM mytable OFFSET floor(random()*N) LIMIT 1;
Consider a table of 2 rows; random()*N generates 0 <= x < 2 and for example SELECT myid FROM mytable OFFSET 1.7 LIMIT 1; returns 0 rows because of implicit rounding to nearest int.
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Pointers in C: when to use the ampersand and the asterisk?
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622
You have pointers and values:
int* p; // variable p is pointer to integer type
int i; // integ...
Putting an if-elif-else statement on one line?
...t's less readable:
>>> i=100
>>> a = 1 if i<100 else 2 if i>100 else 0
>>> a
0
>>> i=101
>>> a = 1 if i<100 else 2 if i>100 else 0
>>> a
2
>>> i=99
>>> a = 1 if i<100 else 2 if i>100 else 0
>>> a
1
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List comprehension vs map
...n map needs a lambda:
$ python -mtimeit -s'xs=range(10)' 'map(lambda x: x+2, xs)'
100000 loops, best of 3: 4.24 usec per loop
$ python -mtimeit -s'xs=range(10)' '[x+2 for x in xs]'
100000 loops, best of 3: 2.32 usec per loop
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What is the proper way to format a multi-line dict in Python?
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242
I use #3. Same for long lists, tuples, etc. It doesn't require adding any extra spaces beyond ...
Benchmarking (python vs. c++ using BLAS) and (numpy)
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jfsjfs
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How can I add new keys to a dictionary?
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edited Jun 11 at 8:28
cs95
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answered ...
Debugging in Clojure? [closed]
...selected functions.
(use 'clojure.contrib.trace)
(defn fib[n] (if (< n 2) n (+ (fib (- n 1)) (fib (- n 2)))))
(dotrace [fib] (fib 3))
produces the output:
TRACE t4425: (fib 3)
TRACE t4426: | (fib 2)
TRACE t4427: | | (fib 1)
TRACE t4427: | | => 1
TRACE t4428: | | (fib 0...
Integer division with remainder in JavaScript?
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edited Feb 21 '17 at 8:50
bluish
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