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Delete rows from a pandas DataFrame based on a conditional expression involving len(string) giving K
...faster than drop:
%%timeit
test = pd.DataFrame({'x': np.random.randn(int(1e6))})
test = test[test.x < 0]
# 54.5 ms ± 2.02 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)
%%timeit
test = pd.DataFrame({'x': np.random.randn(int(1e6))})
test.drop(test[test.x > 0].index, inplace=True)
#...
How to use > in an xargs command?
...
lhunathlhunath
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How to debug Lock wait timeout exceeded on MySQL?
...x 36646234376337652d376630302d303030312d353166322d3431326132346664656366352e6d7033; asc 6db47c7e-7f00-0001-51f2-412a24fdecf5.mp3;; 7: len 21; hex 416e67656c73204e6f7720436f6e666572656e6365; asc Angels Now Conference;; 8: len 34; hex 416e67656c73204e6f7720436f6e666572656e6365204a756c7920392c203230313...
Convert a timedelta to days, hours and minutes
...t to take into account fractions of a second
seconds += td.microseconds / 1e6
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How can I specify the base for Math.log() in JavaScript?
...ion with selective rounding: (Math.round(Math.log(1000) / Math.LN10 * 1e6) / 1e6)
– Shane Daniel
Nov 21 '13 at 5:01
...
Detect if value is number in MySQL
... values ('00.00'),('+1'),('.123'),('-.23e4'),('12.e-5'),('3.5e+6'),('a'),('e6'),('+e0');
select
col1,
col1 + 0 as casted,
col1 REGEXP '^[+-]?[0-9]*([0-9]\\.|[0-9]|\\.[0-9])[0-9]*(e[+-]?[0-9]+)?$' as isNumeric
from myTable;
Result:
col1 | casted | isNumeric
-------|---------|----------
...
Random number generation in C++11: how to generate, how does it work? [closed]
...nd you had this distribution of numbers:
1: 1%
2: 80%
3: 5%
4: 5%
5: 9%
2 is generated FAR more often than any other number, so it is more likely to be produced than other numbers. If all numbers were equally like you would have a 20% chance of getting each number every time. To say it ano...
Set transparent background of an imageview on Android
...ctor.
Some opacity code:
Hex Opacity Values
100% — FF
95% — F2
90% — E6
85% — D9
80% — CC
75% — BF
70% — B3
65% — A6
60% — 99
55% — 8C
50% — 80
45% — 73
40% — 66
35% — 59
30% — 4D
25% — 40
20% — 33
15% — 26
10% — 1A
5% — 0D
0% — 00
You can also set opacit...
Remove columns from dataframe where ALL values are NA
...tion(x)!all(is.na(x))))),with=F]
examples using large data (30 columns, 1e6 rows)
big_data <- replicate(10, data.frame(rep(NA, 1e6), sample(c(1:8,NA),1e6,T), sample(250,1e6,T)),simplify=F)
bd <- do.call(data.frame,big_data)
names(bd) <- paste0('X',seq_len(30))
DT <- as.data.table(bd)
...
gradle build fails on lint task
...e inspiration from
https://android.googlesource.com/platform/tools/base/+/e6a5b9c7c1bca4da402de442315b5ff1ada819c7
(implementation:
https://android.googlesource.com/platform/tools/base/+/e6a5b9c7c1bca4da402de442315b5ff1ada819c7/build-system/gradle/src/main/groovy/com/android/build/gradle/interna...