大约有 7,000 项符合查询结果（耗时：0.0182秒） [XML]
Naming returned columns in Pandas aggregate function? [duplicate]
...OLUMN (SERIES) ====
# Syntax soon to be deprecated
df.groupby('A').B.agg({'foo': 'count'})
# Recommended replacement syntax
df.groupby('A').B.agg(['count']).rename(columns={'count': 'foo'})
# ==== MULTI COLUMN ====
# Syntax soon to be deprecated
df.groupby('A').agg({'B': {'foo': 'sum'}, 'C': {'bar'...
are there dictionaries in javascript like python?
...ed, which is a dictionary implementation:
var dict = new Map();
dict.set("foo", "bar");
//returns "bar"
dict.get("foo");
Unlike javascript's normal objects, it allows any object as a key:
var foo = {};
var bar = {};
var dict = new Map();
dict.set(foo, "Foo");
dict.set(bar, "Bar");
//returns "B...
How to pass command line arguments to a rake task
...ays:
namespace :thing do
desc "it does a thing"
task :work, [:option, :foo, :bar] do |task, args|
puts "work", args
end
task :another, [:option, :foo, :bar] do |task, args|
puts "another #{args}"
Rake::Task["thing:work"].invoke(args[:option], args[:foo], args[:bar])
# or s...
How do I check if an integer is even or odd? [closed]
...nness(object o)
{
if (o == null)
return Evenness.Unknown;
string foo = o.ToString();
if (String.IsNullOrEmpty(foo))
return Evenness.Unknown;
char bar = foo[foo.Length - 1];
switch (bar)
{
case '0':
case '2':
case '4':
case '6':
case '8':
retur...
git pull while not in a git directory
...a different directory without leaving the current directory:
(cd ~/foo && git status)
git --git-dir=~/foo/.git --work-tree=~/foo status
GIT_DIR=~/foo/.git GIT_WORK_TREE=~/foo git status
(cd ../..; git grep foo)
for d in d1 d2 d3; do (cd $d && git svn rebase); done
...
What does curly brackets in the `var { … } = …` statements do?
...perties from objects into distinct variables.
Eg: Array Destructuring
var foo = ["one", "two", "three"];
//without destructuring
var one = foo[0];
var two = foo[1];
var three = foo[2];
// with destructuring
var[one,two,three] = foo
Eg: Object Destructuring
var o = {p: 42, q: true};
var ...
How do I return multiple values from a function in C?
... Tuple getPair() {
Tuple r = { 1, getString() };
return r;
}
void foo() {
struct Tuple t = getPair();
}
2: Use pointers to pass out values.
void getPair(int* a, string* b) {
// Check that these are not pointing to NULL
assert(a);
assert(b);
*a = 1;
*b = getString(...
Using sed and grep/egrep to search and replace
...d separator. This is important to match the -Z of egrep and to avoid being fooled by spaces and newlines in input filenames.
-l: use one line per command as parameter
sed: the stream editor
-i: replace the input file with the output without making a backup
-e: use the following argument as expres...
Curious null-coalescing operator custom implicit conversion behaviour
... analysis but before code generation -- we reduce the expression
result = Foo() ?? y;
from the example above to the moral equivalent of:
A? temp = Foo();
result = temp.HasValue ?
new int?(A.op_implicit(Foo().Value)) :
y;
Clearly that is incorrect; the correct lowering is
result = te...
Add only non-whitespace changes
...is works
git stash && git stash apply && git diff -w > foo.patch && git checkout . && git apply foo.patch && rm foo.patch
I don't like the stashes, but I have run into a bug in git + cygwin where I lose changes, so to make sure that stuff went to the ref...