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Warning message: In `…` : invalid factor level, NA generated
... of 2 variables:
$ Type : Factor w/ 1 level "": NA 1 1
$ Amount: chr "100" "0" "0"
>
> fixed <- data.frame("Type" = character(3), "Amount" = numeric(3),stringsAsFactors=FALSE)
> fixed[1, ] <- c("lunch", 100)
> str(fixed)
'data.frame': 3 obs. of 2 variables:
$ Type : chr ...
Create an empty object in JavaScript with {} or new Object()?
... Array(); over []; - with one minor exception:
var emptyArray = new Array(100);
creates a 100 item long array with all slots containing undefined - which may be nice/useful in certain situations (such as (new Array(9)).join('Na-Na ') + 'Batman!').
My recommendation
Never use new Object(); - i...
Java switch statement multiple cases
...l the time:
switch (variable)
{
case 5:
case 6:
etc.
case 100:
doSomething();
break;
}
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How to clear the interpreter console?
...
Well, here's a quick hack:
>>> clear = "\n" * 100
>>> print clear
>>> ...do some other stuff...
>>> print clear
Or to save some typing, put this file in your python search path:
# wiper.py
class Wipe(object):
def __repr__(self):
...
how to find host name from IP with out login to the host
...
For Windows, try:
NBTSTAT -A 10.100.3.104
or
ping -a 10.100.3.104
For Linux, try:
nmblookup -A 10.100.3.104
They are almost same.
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Join a list of strings in python and wrap each string in quotation marks
...t;> timeit.Timer("""words = ['hello', 'world', 'you', 'look', 'nice'] * 100; ', '.join('"{0}"'.format(w) for w in words)""").timeit(1000)
0.32559704780578613
>>> timeit.Timer("""words = ['hello', 'world', 'you', 'look', 'nice'] * 100; '"{}"'.format('", "'.join(words))""").timeit(1000)
0...
Maintaining the final state at end of a CSS3 animation
...fter animation ends. for example if your animation changes width from 0 to 100px, this property makes sure the element remains 100px wide after animation ends.
– Farzad YZ
Feb 17 '16 at 15:23
...
How do I create a nice-looking DMG for Mac OS X using command-line tools?
...ner window to false
set the bounds of container window to {400, 100, 885, 430}
set theViewOptions to the icon view options of container window
set arrangement of theViewOptions to not arranged
set icon size of theViewOptions to 72
set background...
When NOT to use Cassandra?
... cause real problems with banks. Scenario:You have one bank account, with $100 on above the limit on it, and two bank cards. When you try to withdraw money with the two cards at the same time at 2 different ATMs, you will get 2 times $100, and a letter with an extra fee in your mail box. The bank ea...
How does the Java 'for each' loop work?
... the testing class at the bottom of this post, which sums the numbers in a 100-element primitive-int array (A is iterator, B is index):
[C:\java_code\]java TimeIteratorVsIndexIntArray 1000000
Test A: 358,597,622 nanoseconds
Test B: 269,167,681 nanoseconds
B faster by 89,429,941 nanoseconds (24.4387...