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How to access pandas groupby dataframe by key
...
You can use the get_group method:
In [21]: gb.get_group('foo')
Out[21]:
A B C
0 foo 1.624345 5
2 foo -0.528172 11
4 foo 0.865408 14
Note: This doesn't require creating an intermediary dictionary / copy of every subdataframe for every group, so will be muc...
redirect COPY of stdout to log file from within bash script itself
...al from him by simply
# adding his answer to mine.
exec 2>&1
echo "foo"
echo "bar" >&2
Note that this is bash, not sh. If you invoke the script with sh myscript.sh, you will get an error along the lines of syntax error near unexpected token '>'.
If you are working with signal tr...
Explicitly calling return in a function or not
...ction and easily see all exit points and values.
Paul used this example:
foo = function() {
if(a) {
return(a)
} else {
return(b)
}
}
Unfortunately, one could point out that it can easily be rewritten as:
foo = function() {
if(a) {
output <- a
} else {
output <- b
}
outpu...
RAII and smart pointers in C++
...e stack. For instance (and stealing an example from another answer):
void foo() {
std::string str;
// Do cool things to or using str
}
This works fine - but what if we want to return str? We could write this:
std::string foo() {
std::string str;
// Do cool things to or using str
...
Selecting element by data attribute
...ugin. This allows you to write even more readable code by using .dataAttr('foo'), and results in a smaller file size after minification (compared to using .attr('data-foo')).
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How to write a bash script that takes optional input arguments?
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You could use the default-value syntax:
somecommand ${1:-foo}
The above will, as described in Bash Reference Manual - 3.5.3 Shell Parameter Expansion [emphasis mine]:
If parameter is unset or null, the expansion of word is substituted. Otherwise, the value of parameter is sub...
Catch an exception thrown by an async void method
...ubble up to the calling code - but only if you await or Wait() the call to Foo.
public async Task Foo()
{
var x = await DoSomethingAsync();
}
public async void DoFoo()
{
try
{
await Foo();
}
catch (ProtocolException ex)
{
// The exception will be caught be...
Instantiating a generic class in Java [duplicate]
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Why not pass new Foo() as argument?
– fastcodejava
Mar 12 '10 at 12:04
2
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How to import module when module name has a '-' dash or hyphen in it?
I want to import foo-bar.py. This works:
5 Answers
5
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How can I reliably determine the type of a variable that is declared using var at design time?
... type of a particular expression inside a method body -- say you've typed "foo." and we need to figure out what are the members of foo -- we do the same thing; we skip as much work as we reasonably can.
We start with a pass which analyzes only the local variable declarations within that method. W...