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What's the difference between eval, exec, and compile?
...ession, and exec is used to execute dynamically generated Python code only for its side effects.
eval and exec have these two differences:
eval accepts only a single expression, exec can take a code block that has Python statements: loops, try: except:, class and function/method definitions and s...
Object comparison in JavaScript [duplicate]
...
Unfortunately there is no perfect way, unless you use _proto_ recursively and access all non-enumerable properties, but this works in Firefox only.
So the best I can do is to guess usage scenarios.
1) Fast and limited.
Wor...
Should import statements always be at the top of a module?
...ing shows that would help (you did profile to see where best to improve performance, right??)
The best reasons I've seen to perform lazy imports are:
Optional library support. If your code has multiple paths that use different libraries, don't break if an optional library is not installed.
In t...
Activate a virtualenv via fabric as deploy user
..., Fabric has a prefix context manager which uses this technique so you can for example:
def task():
with prefix('workon myvenv'):
run('git pull')
run('do other stuff, etc')
* There are bound to be cases where using the command1 && command2 approach may blow up on you...
How efficient is locking an unlocked mutex? What is the cost of a mutex?
...d gives me or whatever the native system library provides) or a single one for an object.
5 Answers
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How do I find out which keystore was used to sign an app?
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Thank you for this. I added a tool for doing this to my github project. github.com/RichardBronosky/ota-tools/blob/master/…
– Bruno Bronosky
Aug 1 '14 at 19:43
...
“where 1=1” statement [duplicate]
...ue = "Toyota" you don't have to worry about whether there is a condition before or just WHERE. The optimiser should ignore it
No magic, just practical
Example Code:
commandText = "select * from car_table where 1=1";
if (modelYear <> 0) commandText += " and year="+modelYear
if (manufa...
Python Progress Bar
...dout.write("\b" * (toolbar_width+1)) # return to start of line, after '['
for i in xrange(toolbar_width):
time.sleep(0.1) # do real work here
# update the bar
sys.stdout.write("-")
sys.stdout.flush()
sys.stdout.write("]\n") # this ends the progress bar
Note: progressbar2 is a for...
How can I get all the request headers in Django?
...import re
regex = re.compile('^HTTP_')
dict((regex.sub('', header), value) for (header, value)
in request.META.items() if header.startswith('HTTP_'))
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how do you filter pandas dataframes by multiple columns
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Using & operator, don't forget to wrap the sub-statements with ():
males = df[(df[Gender]=='Male') & (df[Year]==2014)]
To store your dataframes in a dict using a for loop:
from collections import defaultdict
dic={}
for g in ['male', 'female'...