大约有 7,000 项符合查询结果（耗时：0.0207秒） [XML]
How to take column-slices of dataframe in pandas
...ement.
Let's assume we have a DataFrame with the following columns:
foo, bar, quz, ant, cat, sat, dat.
# selects all rows and all columns beginning at 'foo' up to and including 'sat'
df.loc[:, 'foo':'sat']
# foo bar quz ant cat sat
.loc accepts the same slice notation that Python lists do...
Store boolean value in SQLite
...alse and true. You could declare the column type like this:
CREATE TABLE foo(mycolumn BOOLEAN NOT NULL CHECK (mycolumn IN (0,1)));
Omit the NOT NULL if you want to allow NULL in addition to 0 and 1.
The use of the type name BOOLEAN here is for readability, to SQLite it's just a type with NUMERI...
How to use CMAKE_INSTALL_PREFIX
...ists.txt
cmake_minimum_required (VERSION 2.8)
set (CMAKE_INSTALL_PREFIX /foo/bar/bubba)
message("CIP = ${CMAKE_INSTALL_PREFIX} (should be /foo/bar/bubba")
project (BarkBark)
message("CIP = ${CMAKE_INSTALL_PREFIX} (should be /foo/bar/bubba")
set (CMAKE_INSTALL_PREFIX /foo/bar/bubba)
message("CIP = ...
How to replace a string in multiple files in linux command line
...
cd /path/to/your/folder
sed -i 's/foo/bar/g' *
Occurrences of "foo" will be replaced with "bar".
On BSD systems like macOS, you need to provide a backup extension like -i '.bak' or else "risk corruption or partial content" per the manpage.
cd /path/to/you...
Express-js wildcard routing to cover everything under and including a path
I'm trying to have one route cover everything under /foo including /foo itself. I've tried using /foo* which work for everything except it doesn't match /foo . Observe:
...
How to get next/previous record in MySQL?
...
next:
select * from foo where id = (select min(id) from foo where id > 4)
previous:
select * from foo where id = (select max(id) from foo where id < 4)
share
...
Execution of Python code with -m option or not
...t when you try to run a package. There is a big difference between:
python foo/bar/baz.py
and
python -m foo.bar.baz
as in the latter case, foo.bar is imported and relative imports will work correctly with foo.bar as the starting point.
Demo:
$ mkdir -p test/foo/bar
$ touch test/foo/__init__.py
$ t...
What is the purpose of the “final” keyword in C++11 for functions?
...to be able to mark a non-virtual method as 'final'. Given
struct A { void foo(); };
struct B : public A { void foo(); };
A * a = new B;
a -> foo(); // this will call A :: foo anyway, regardless of whether there is a B::foo
a->foo() will always call A::foo.
But, if A::foo was virtual, then ...
Shorthand way for assigning a single field in a record, while copying the rest of the fields?
...e's a nice way of updating record fields. In GHCi you can do --
> data Foo = Foo { a :: Int, b :: Int, c :: String } -- define a Foo
> let foo = Foo { a = 1, b = 2, c = "Hello" } -- create a Foo
> let updateFoo x = x { c = "Goodbye" } -- function to update Foos
> ...
How do I check that multiple keys are in a dict in a single pass?
...
Well, you could do this:
>>> if all (k in foo for k in ("foo","bar")):
... print "They're there!"
...
They're there!
share
|
improve this answer
|
...