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Python argparse mutual exclusive group
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add_mutually_exclusive_group doesn't make an entire group mutually exclusive. It makes options within the group mutually exclusive.
What you're looking for is subcommands. Instead of prog [ -a xxxx | [-b yyy -c zzz]], you'd have:
prog
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Why does this assert throw a format exception when comparing structures?
...quality of two System.Drawing.Size structures, and I'm getting a format exception instead of the expected assert failure.
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How do I do base64 encoding on iOS?
..., 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
};
@implementatio...
Using arrays or std::vectors in C++, what's the performance gap?
...rom the internet):
// Comparison of assembly code generated for basic indexing, dereferencing,
// and increment operations on vectors and arrays/pointers.
// Assembly code was generated by gcc 4.1.0 invoked with g++ -O3 -S on a
// x86_64-suse-linux machine.
#include <vector>
struct S
{...
When should I use double instead of decimal?
... if you were doing the calculation by hand. It depends greatly on the context (how many operations you're performing) whether these errors are significant enough to warrant much thought however.
In all cases, if you want to compare two floating-point numbers that should in theory be equivalent (b...
Python: Select subset from list based on index set
...t use from itertools import izip and use that instead of zip in the first example. That creates an iterator, same as Python 3.
– Chris B.
Jul 5 '10 at 20:34
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What does glLoadIdentity() do in OpenGL?
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The identity matrix, in terms of the projection and modelview matrices, essentially resets the matrix back to its default state.
As you hopefully know, glTranslate and glRotate are always relative to the matrix's current state. So for instanc...
With bash, how can I pipe standard error into another process?
... the file as follows:
process1 2> >(process2)
Here is a concrete example that sends stderr to both the screen and appends to a logfile
sh myscript 2> >(tee -a errlog)
share
|
improv...
Does List guarantee insertion order?
...d in the list in the order you add them, including duplicates, unless you explicitly sort the list.
According to MSDN:
...List "Represents a strongly typed list of objects that can be
accessed by index."
The index values must remain reliable for this to be accurate. Therefore the order is g...
What is array to pointer decay?
...red as int numbers [5] cannot be re-pointed, i.e. you can't say numbers = 0x5a5aff23. More importantly the term decay signifies loss of type and dimension; numbers decay into int* by losing the dimension information (count 5) and the type is not int [5] any more. Look here for cases where the decay ...