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Checking if a string can be converted to float in Python
... ------------
print(isfloat("")) False
print(isfloat("1234567")) True
print(isfloat("NaN")) True nan is also float
print(isfloat("NaNananana BATMAN")) False
print(isfloat("123.456")) True
print(isfloat("123.E4")) ...
How can I make a horizontal ListView in Android? [duplicate]
...) There is no recycling of views. Maybe it would be possible to tack this functionality onto the scroll view, but it seems to me that it would mess with the scrolling behavior, and it would be nearly as much work as simply extending AdapterView.
– Neil Traft
O...
Play sound on button click android
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mp = MediaPlayer.create(context, R.raw.sound_two);
and play it !
Have fun!
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How to detect when an Android app goes to the background and come back to the foreground
...to a Google I/O talk:
class YourApplication : Application() {
override fun onCreate() {
super.onCreate()
registerActivityLifecycleCallbacks(AppLifecycleTracker())
}
}
class AppLifecycleTracker : Application.ActivityLifecycleCallbacks {
private var numStarted = 0
override fun ...
Dynamic SQL - EXEC(@SQL) versus EXEC SP_EXECUTESQL(@SQL)
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EXEC('SELECT * FROM FOO WHERE ID=?', 123) will replace the parameter placeholder "?" with the value 123 and then execute the query, returning a result for SELECT * FROM FOO WHERE ID=123
– Peter Wone
Jun 1 '10 at 23:27
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sed: print only matching group
...it with a 2nd grep.
# To extract \1 from /xx([0-9]+)yy/
$ echo "aa678bb xx123yy xx4yy aa42 aa9bb" | grep -Eo 'xx[0-9]+yy' | grep -Eo '[0-9]+'
123
4
# To extract \1 from /a([0-9]+)b/
$ echo "aa678bb xx123yy xx4yy aa42 aa9bb" | grep -Eo 'a[0-9]+b' | grep -Eo '[0-9]+'
678
9
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How to get a reference to current module's attributes in Python
...ke pytest:
*** foo ... ..
*** boo ... ..
*** runtest c:\python\x86\37\lib\site-packages\xonsh\pytest_plugin.py 58
*** pytest_runtest_call c:\python\x86\37\lib\site-packages\_pytest\runner.py 125
*** _multicall c:\python\x86\37\lib\site-packages\pluggy\callers.py 187
*** <lambda> c:\python\x86...
What does the “yield” keyword do?
...one, etc. And generators return... well that's where yield comes in:
def f123():
yield 1
yield 2
yield 3
for item in f123():
print item
Instead of yield statements, if you had three return statements in f123() only the first would get executed, and the function would exit. But f1...
Revert the `--no-site-packages` option with virtualenv
I have created a virtualenv using the --no-site-packages option and installed lots of libraries. Now I would like to revert the --no-site-packages option and use also the global packages.
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module.exports vs exports in Node.js
...:
var x = require('file1.js');
contents of file1.js:
module.exports = '123';
When the above statement is executed, a Module object is created. Its constructor function is:
function Module(id, parent) {
this.id = id;
this.exports = {};
this.parent = parent;
if (parent &&...