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Which is the preferred way to concatenate a string in Python?
... to a string, then to a list:
a += b:
0.10780501365661621
a.append(b):
0.1123361587524414
OK, turns out that even when the resulting string is a million characters long, appending was still faster.
Now let's try with appending a thousand character long string a hundred thousand times:
a += b:
0...
Is there any difference between GROUP BY and DISTINCT
...ukas Eder
171k105105 gold badges562562 silver badges12371237 bronze badges
...
Using bitwise OR 0 to floor a number
...number.
Math.trunc(13.37) // 13
Math.trunc(42.84) // 42
Math.trunc(0.123) // 0
Math.trunc(-0.123) // -0
Math.trunc("-1.123")// -1
Math.trunc(NaN) // NaN
Math.trunc("foo") // NaN
Math.trunc() // NaN
sh...
Get folder name from full file path
... answered Jun 27 '18 at 15:39
123iamking123iamking
1,48011 gold badge2020 silver badges3434 bronze badges
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How to determine whether an object has a given property in JavaScript
...throw new Error("IllegalArgumentException");
}
alert("ok");
}
f({req1: 123}); // error
f({req1: 123, req2: 456}); // ok
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How to sign an android apk file
...pp -keyalg RSA -keysize 2048 -validity 10000
keystore password : yourApp@123
key password : yourApp@123
CMD O/P
D:\ru\SignedBuilds\MySignedApp>keytool -genkey -v -keystore id.keystore
-alias MySignedApp -keyalg RSA -keysize 2048 -validity 10000
Enter keystore password:
Re-enter new pass...
How to overcome TypeError: unhashable type: 'list'
... else:
d[key] = [value]
print d
# {'AAA': ['111', '112'], 'AAC': ['123'], 'AAB': ['111']}
Note that if you are using Python 3.x, you'll have to make a minor adjustment to get it work properly. If you open the file with rb, you'll need to use line = line.split(b'x') (which makes sure you ar...
Using reflect, how do you set the value of a struct field?
...oo struct {
Number int
Text string
}
func main() {
foo := Foo{123, "Hello"}
fmt.Println(int(reflect.ValueOf(foo).Field(0).Int()))
reflect.ValueOf(&foo).Elem().Field(0).SetInt(321)
fmt.Println(int(reflect.ValueOf(foo).Field(0).Int()))
}
Prints:
123
321
...
Static/Dynamic vs Strong/Weak
...kly typed that "12" + "34" would equal "46", but "12" + "34Q" would equal "1234Q" [fortunately, one could write "12" & "34" if one wanted concatenation]. Curiously, variables holding numbers stored them as double-precision floats, and math on such variables used the floating-point values without...
Microsecond timing in JavaScript
...returns the number of microseconds in the fractional (e.g. a value of 1000.123 is 1 second and 123 microseconds).
now() is monotonically increasing. This is important as Date.getTime() can possibly jump forward or even backward on subsequent calls. Notably, if the OS's system time is updated (e.g....