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Numpy - add row to array
...e necessary after every row, it's much quicker to add rows in python, then convert to numpy. Here are timing tests using python 3.6 vs. numpy 1.14, adding 100 rows, one at a time:
import numpy as np
from time import perf_counter, sleep
def time_it():
# Compare performance of two methods for a...
Read file line by line using ifstream in C++
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#include <fstream>
std::ifstream infile("thefile.txt");
The two standard methods are:
Assume that every line consists of two numbers and read token by token:
int a, b;
while (infile >> a >> b)
{
// process pair (a,b)
}
Line-based parsing, using string streams:
#include ...
How to sort by two fields in Java?
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@Ralph: I have amended my answer, and added a brief description.
– Richard H
Jan 26 '11 at 14:53
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Drop data frame columns by name
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the subset function works better as it won't convert a data frame with one column into a vector
– mut1na
Jun 28 '13 at 9:06
3
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How do I make a composite key with SQL Server Management Studio?
...ht multiple fields, click the blocks in front of the columns "column name" and "data type" and such. Ctrl/Shift+Clicking on the column name fields won't actually do anything.
– Pimgd
Oct 10 '13 at 14:50
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Split a List into smaller lists of N size
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So if I have a List length zillion, and I want to split into smaller lists Length 30, and from every smaller list I only want to Take(1), then I still create lists of 30 items of which I throw away 29 items. This can be done smarter!
– Har...
How do I get the height and width of the Android Navigation Bar programmatically?
...lack navigation bar on the bottom of the screen is not easily removable in Android. It has been part of Android since 3.0 as a replacement for hardware buttons. Here is a picture:
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Remove Item from ArrayList
I have an ArrayList suppose list , and it has 8 items A-H and now I want to delete 1,3,5 position Item stored in int array from the list how can I do this.
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How can I use a DLL file from Python?
...y.
hllDll = ctypes.WinDLL ("c:\\PComm\\ehlapi32.dll")
# Set up prototype and parameters for the desired function call.
# HLLAPI
hllApiProto = ctypes.WINFUNCTYPE (
ctypes.c_int, # Return type.
ctypes.c_void_p, # Parameters 1 ...
ctypes.c_void_p,
ctypes.c_void_p,
ctypes.c...
Getting the first and last day of a month, using a given DateTime object
I want to get the first day and last day of the month where a given date lies in. The date comes from a value in a UI field.
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