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How expensive is the lock statement?
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Here is an article that goes into the cost. Short answer is 50ns.
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Delete rows from a pandas DataFrame based on a conditional expression involving len(string) giving K
...tion>].index)
Example
To remove all rows where column 'score' is < 50:
df = df.drop(df[df.score < 50].index)
In place version (as pointed out in comments)
df.drop(df[df.score < 50].index, inplace=True)
Multiple conditions
(see Boolean Indexing)
The operators are: | for or, &am...
Change Canvas.Left property in code behind?
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Canvas.SetLeft(theObject, 50)
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jQuery SVG, why can't I addClass?
...ssue.
– Joao Arruda
Sep 8 '16 at 19:50
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How can I wrap or break long text/word in a fixed width span?
... too long for your span width.
span {
display:block;
width:150px;
word-wrap:break-word;
}
<span>VeryLongLongLongLongLongLongLongLongLongLongLongLongExample</span>
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Breaking out of nested loops [duplicate]
...xrange(10):
for y in xrange(10):
print x*y
if x*y > 50:
break
else:
continue # only executed if the inner loop did NOT break
break # only executed if the inner loop DID break
The same works for deeper loops:
for x in xrange(10):
for y in xr...
How to determine total number of open/active connections in ms sql server 2005
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edited Apr 27 '13 at 7:50
Sebastian
4,97544 gold badges2828 silver badges4545 bronze badges
answered ...
Changing CSS Values with Javascript
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edited Sep 28 '12 at 15:50
Luis Perez
25.5k1010 gold badges6969 silver badges7575 bronze badges
answer...
SQL Server Insert if not exists
...on executes the INSERT, i.e. a race condition. See stackoverflow.com/a/3791506/1836776 for a good answer on why even wrapping in a transaction doesn't solve this.
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How do I calculate percentiles with python/numpy?
...py too.
import numpy as np
a = np.array([1,2,3,4,5])
p = np.percentile(a, 50) # return 50th percentile, e.g median.
print p
3.0
This ticket leads me to believe they won't be integrating percentile() into numpy anytime soon.
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