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Cost of exception handlers in Python
...ve just tried the following:
import timeit
statements=["""\
try:
b = 10/a
except ZeroDivisionError:
pass""",
"""\
if a:
b = 10/a""",
"b = 10/a"]
for a in (1,0):
for s in statements:
t = timeit.Timer(stmt=s, setup='a={}'.format(a))
print("a = {}\n{}".format(a,s))
...
MySQL select 10 random rows from 600K rows fast
How can I best write a query that selects 10 rows randomly from a total of 600k?
26 Answers
...
Why does range(start, end) not include end?
...
Because it's more common to call range(0, 10) which returns [0,1,2,3,4,5,6,7,8,9] which contains 10 elements which equals len(range(0, 10)). Remember that programmers prefer 0-based indexing.
Also, consider the following common code snippet:
for i in range(len(li))...
Regular expression to limit number of characters to 10
...te a regular expression that will only allow lowercase letters and up to 10 characters. What I have so far looks like this:
...
CSS '>' selector; what is it? [duplicate]
...ese rules). See fiddle.
div {
border: 1px solid black;
padding: 10px;
}
.outer > div {
border: 1px solid orange;
}
<div class='outer'>
div.outer - This is the parent.
<div class="middle">
div.middle - This is an immediate child of "outer". This will receiv...
All combinations of a list of lists
...t:
>>> import itertools
>>> a = [[1,2,3],[4,5,6],[7,8,9,10]]
>>> list(itertools.product(*a))
[(1, 4, 7), (1, 4, 8), (1, 4, 9), (1, 4, 10), (1, 5, 7), (1, 5, 8), (1, 5, 9), (1, 5, 10), (1, 6, 7), (1, 6, 8), (1, 6, 9), (1, 6, 10), (2, 4, 7), (2, 4, 8), (2, 4, 9), (2, 4, 10)...
Correct way to populate an Array with a Range in Ruby
...
You can create an array with a range using splat,
>> a=*(1..10)
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
using Kernel Array method,
Array (1..10)
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
or using to_a
(1..10).to_a
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
...
Oracle SELECT TOP 10 records
...e an big problem with an SQL Statement in Oracle. I want to select the TOP 10 Records ordered by STORAGE_DB which aren't in a list from an other select statement.
...
How can I convert this foreach code to Parallel.ForEach?
...8
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微软正式推送Win10，不满意或者不习惯可以回滚至旧版 - 资讯 - 清泛网 - 专...
微软正式推送Win10，不满意或者不习惯可以回滚至旧版今天无疑是微软新款操作系统Win10的大日子，被视作继Win7之后又一个能够带微软重回巅峰的系统作品，Win10推送全面开启，Win7、Win8用户从今日零点起就可以免费升级到Win10，...