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Looping over arrays, printing both index and value
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You would find the array keys with "${!foo[@]}" (reference), so:
for i in "${!foo[@]}"; do
printf "%s\t%s\n" "$i" "${foo[$i]}"
done
Which means that indices will be in $i while the elements themselves have to be accessed via ${foo[$i]}
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How to decorate a class?
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Example:
def substitute_init(self, id, *args, **kwargs):
pass
class FooMeta(type):
def __new__(cls, name, bases, attrs):
attrs['__init__'] = substitute_init
return super(FooMeta, cls).__new__(cls, name, bases, attrs)
class Foo(object):
__metaclass__ = FooMeta
d...
How to select rows from a DataFrame based on column values?
... example,
import pandas as pd
import numpy as np
df = pd.DataFrame({'A': 'foo bar foo bar foo bar foo foo'.split(),
'B': 'one one two three two two one three'.split(),
'C': np.arange(8), 'D': np.arange(8) * 2})
print(df)
# A B C D
# 0 foo one ...
Overloading Macro on Number of Arguments
I have two macros FOO2 and FOO3 :
8 Answers
8
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How to remove/delete a large file from commit history in Git repository?
...-name-status
* f772d66 (HEAD, master) Login page
| A login.html
* cb14efd Remove DVD-rip
| D oops.iso
* ce36c98 Careless
| A oops.iso
| A other.html
* 5af4522 Admin page
| A admin.html
* e738b63 Index
A index.html
Note that git lola is a non-standard but highly useful ali...
Using property() on classmethods
...method property, create the property on the metaclass.
>>> class foo(object):
... _var = 5
... class __metaclass__(type): # Python 2 syntax for metaclasses
... pass
... @classmethod
... def getvar(cls):
... return cls._var
... @classmethod
... def s...
Creating an instance of class
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/* 1 */ Foo* foo1 = new Foo ();
Creates an object of type Foo in dynamic memory. foo1 points to it. Normally, you wouldn't use raw pointers in C++, but rather a smart pointer. If Foo was a POD-type, this would perform value-initial...
Namespace and class with the same name?
...d up in this unfortunate situation: you are writing Blah.DLL and
importing Foo.DLL and Bar.DLL, which, unfortunately, both have a type
called Foo:
// Foo.DLL:
namespace Foo { public class Foo { } }
// Bar.DLL:
namespace Bar { public class Foo { } }
// Blah.DLL:
namespace Blah
{
using Foo; ...
The easiest way to transform collection to array?
Suppose we have a Collection<Foo> . What is the best (shortest in LoC in current context) way to transform it to Foo[] ? Any well-known libraries are allowed.
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How do you perform a left outer join using linq extension methods
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For a (left outer) join of a table Bar with a table Foo on Foo.Foo_Id = Bar.Foo_Id in lambda notation:
var qry = Foo.GroupJoin(
Bar,
foo => foo.Foo_Id,
bar => bar.Foo_Id,
(x,y) => new { Foo = x, Bars = y })
.SelectMany(...