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Python argparse mutual exclusive group
...
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 hav...
Check if a class has a member function of a given signature
...compile-time. Example from my code (tests if class has member function size_t used_memory() const).
template<typename T>
struct HasUsedMemoryMethod
{
template<typename U, size_t (U::*)() const> struct SFINAE {};
template<typename U> static char Test(SFINAE<U, &U::us...
Avoid duplicates in INSERT INTO SELECT query in SQL Server
...
Using NOT EXISTS:
INSERT INTO TABLE_2
(id, name)
SELECT t1.id,
t1.name
FROM TABLE_1 t1
WHERE NOT EXISTS(SELECT id
FROM TABLE_2 t2
WHERE t2.id = t1.id)
Using NOT IN:
INSERT INTO TABLE_2
(id, name)
SELECT t...
Can't find the PostgreSQL client library (libpq)
...
$ sudo su
$ env ARCHFLAGS="-arch x86_64" gem install pg
Building native extensions. This could take a while...
Successfully installed pg-0.11.0
1 gem installed
Installing ri documentation for pg-0.11.0...
Installing RDoc documentation for pg-0.11.0...
WORKE...
Why doesn't Python have a sign function?
...y removed and replaced by sign! Have you never implemented a class with a __cmp__ method? Have you never called cmp and specified a custom comparator function?
In summary, I've found myself wanting a sign function too, but copysign with the first argument being 1 will work just fine. I disagree ...
Link to all Visual Studio $ variables
... on my machine. Probably not all macros are defined for others (e.g. OCTAVE_EXECUTABLE), but I wanted to err on the side of inclusiveness here.
For example, this is the first time that I see $(Language) (expanding to C++ for this project) being mentioned outside of the IDE.
$(AllowLocalNetworkLoop...
Count the number occurrences of a character in a string
...quently, check out collections.Counter:
from collections import Counter
my_str = "Mary had a little lamb"
counter = Counter(my_str)
print counter['a']
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What is the difference between a mutable and immutable string in C#?
...ring str,
[1] class [mscorlib]System.Text.StringBuilder sb)
IL_0000: nop
IL_0001: ldstr "inital value"
IL_0006: stloc.0
IL_0007: ldstr "\nsecond value"
IL_000c: stloc.0
IL_000d: ldstr "\nthird value"
IL_0012: stloc.0
IL_0013: newobj instance void...
How to identify numpy types in python?
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Use the builtin type function to get the type, then you can use the __module__ property to find out where it was defined:
>>> import numpy as np
a = np.array([1, 2, 3])
>>> type(a)
<type 'numpy.ndarray'>
>>> type(a).__module__
'numpy'
>>> type(a).__m...
using lodash .groupBy. how to add your own keys for grouped output?
...ame": "eddie",
"color": "green",
"age": "77"
}];
console.log(
_.chain(data)
// Group the elements of Array based on `color` property
.groupBy("color")
// `key` is group's name (color), `value` is the array of objects
.map((value, key) => ({ color: key, users: valu...