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What is the difference between a var and val definition in Scala?
...d, and the object assigned to a var can. However, said object can have its internal state modified. For example:
class A(n: Int) {
var value = n
}
class B(n: Int) {
val value = new A(n)
}
object Test {
def main(args: Array[String]) {
val x = new B(5)
x = new B(6) // Doesn't work, be...
python max function using 'key' and lambda expression
...on the type of the objects (for example a string is always greater than an integer).
To modify the object before comparison, or to compare based on a particular attribute/index, you've to use the key argument.
Example 1:
A simple example, suppose you have a list of numbers in string form, but yo...
Android Webview - Completely Clear the Cache
...thod for clearCache() , recursive
//returns number of deleted files
static int clearCacheFolder(final File dir, final int numDays) {
int deletedFiles = 0;
if (dir!= null && dir.isDirectory()) {
try {
for (File child:dir.listFiles()) {
//first del...
Formatting code in Notepad++
... Delete to start of line
Ctrl-Shft-Delete Delete to end of line
Ctrl-U Convert to lower case
Ctrl-Shft-U Convert to UPPER CASE
Ctrl-B Go to matching brace
Ctrl-Shft-R Start to record /Stop recording the macro
Ctrl-Shft-P Play recorded macro
Ctrl-Q Block comment/uncomment
Ctrl-Shft-Q Stream com...
Java 8: performance of Streams vs Collections
...(StreamVsVanilla.N)
public class StreamVsVanilla {
public static final int N = 10000;
static List<Integer> sourceList = new ArrayList<>();
static {
for (int i = 0; i < N; i++) {
sourceList.add(i);
}
}
@Benchmark
public List<Doub...
How to implement a ConfigurationSection with a ConfigurationElementCollection
... <Site Id="123" />
<Lanes>
<Lane Id="1" PointId="north" Direction="Entry"/>
<Lane Id="2" PointId="south" Direction="Exit"/>
</Lanes>
</CustomApplicationConfig>
then you can use my implementation of configuration section so to...
初窥InnoDB的Memcached插件 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...
| c2 | varchar(1024) | YES | | NULL | |
| c3 | int(11) | YES | | NULL | |
| c4 | bigint(20) unsigned | YES | | NULL | |
| c5 | int(11) | YES | | NULL | |
+-------+---------------------+------+-----...
What are the undocumented features and limitations of the Windows FINDSTR command?
..., 0x0B Vertical Tab, 0x0C Form Feed, 0x0D Carriage Return.
XP FINDSTR also converts a number of extended ASCII characters to dots as well. The extended ASCII characters that display as dots on XP are the same as those that are transformed when supplied on the command line. See the "Character limits ...
pandas GroupBy columns with NaN (missing) values
...cient topic, if someone still stumbles over this--another workaround is to convert via .astype(str) to string before grouping. That will conserve the NaN's.
df = pd.DataFrame({'a': ['1', '2', '3'], 'b': ['4', np.NaN, '6']})
df['b'] = df['b'].astype(str)
df.groupby(['b']).sum()
a
b
4 1
6 ...
Confused about __str__ on list in Python [duplicate]
...
Python has two different ways to convert an object to a string: str() and repr(). Printing an object uses str(); printing a list containing an object uses str() for the list itself, but the implementation of list.__str__() calls repr() for the individual it...