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Remap values in pandas column with a dict
...ir values or be converted to NaNs):
Exhaustive Mapping
In this case, the form is very simple:
df['col1'].map(di) # note: if the dictionary does not exhaustively map all
# entries then non-matched entries are changed to NaNs
Although map most commonly takes a funct...
Platform independent size_t Format specifiers in c?
...e_t is unsigned, thus %ld is double wrong: wrong length modifier and wrong format conversion specifier. In case you wonder, %zd is for ssize_t (which is signed).
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How can I do test setup using the testing package in Go
...ion for several testing use cases. TestMain
provides a global hook to perform setup and shutdown, control the
testing environment, run different code in a child process, or check
for resources leaked by test code. Most packages will not need a
TestMain, but it is a welcome addition for those...
How to Deal with Temporary NSManagedObject instances?
... @quellish Agreed. Apple has stated in their recent core data performance talks at WWDC that creating contexts is very lightweight.
– Jesse
Dec 4 '14 at 1:01
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How to create the most compact mapping n → isprime(n) up to a limit N?
...aper.
If you want to find big numbers, look into primes that have special forms like Mersenne primes.
The algorithm I usually implement (easy to understand and code) is as follows (in Python):
def isprime(n):
"""Returns True if n is prime."""
if n == 2:
return True
if n == 3:
...
How to force a web browser NOT to cache images
...for two pro-bono websites. It provides the website administrator with HTML forms for events where they fill the fields (date, place, title, description, links, etc.) and save it. On that form I allow the administrator to upload an image related to the event. On the HTML page displaying the form, I a...
Is there a reason for C#'s reuse of the variable in a foreach?
...
8.8.4 The foreach statement
(...)
A foreach statement of the form
foreach (V v in x) embedded-statement
is then expanded to:
{
E e = ((C)(x)).GetEnumerator();
try {
while (e.MoveNext()) {
V v = (V)(T)e.Current;
embedded-statement
}
}
fina...
How to get the top 10 values in postgresql?
...u can use limit
select *
from scores
order by score desc
limit 10
If performance is important (when is it not ;-) look for an index on score.
Starting with version 8.4, you can also use the standard (SQL:2008) fetch first
select *
from scores
order by score desc
fetch first 10 rows only
A...
Exposing database IDs - security risk?
...ity to control access to an operation. How this is done depends on the platform and framework you've chosen, but many support a declarative security model that will automatically redirect browsers to an authentication step when an action requires some authority.
Use programmatic security to control ...
Merge Images Side by Side(Horizontally)
...
that can be added to a Thunar custom action in this form (ex. to join vertically = up-town):convert -append %F joined-image.png . All selected images will be joined as one png in alphabetical order
– user4098390
Mar 5 '17 at 10:53
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