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Build vs new in Rails 3
In the Rails 3 docs , the build method for associations is described as being the same as the new method, but with the automatic assignment of the foreign key. Straight from the docs:
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Static variables in member functions
...e of i will remain through out the program. To add an example:
A o1, o2, o3;
o1.foo(); // i = 1
o2.foo(); // i = 2
o3.foo(); // i = 3
o1.foo(); // i = 4
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in_array multiple values
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answered Sep 24 '11 at 23:51
Mark ElliotMark Elliot
65.9k1818 gold badges132132 silver badges155155 bronze badges
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filter items in a python dictionary where keys contain a specific string
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183
How about a dict comprehension:
filtered_dict = {k:v for k,v in d.iteritems() if filter_string ...
Take the content of a list and append it to another list
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379
You probably want
list2.extend(list1)
instead of
list2.append(list1)
Here's the differen...
Pandas get topmost n records within each group
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3 Answers
3
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Summarizing multiple columns with dplyr? [duplicate]
...df %>% group_by(grp) %>% summarise_all(list(mean))
#> # A tibble: 3 x 5
#> grp a b c d
#> <int> <dbl> <dbl> <dbl> <dbl>
#> 1 1 3.08 2.98 2.98 2.91
#> 2 2 3.03 3.04 2.97 2.87
#> 3 3 2.85 2.95 2.95 3.06...
How to remove last n characters from every element in the R vector
...rame("data"=char_array,"data2"=1:4)
a$data = substr(a$data,1,nchar(a$data)-3)
a should now contain:
data data2
1 foo_ 1
2 bar_ 2
3 ap 3
4 b 4
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Implementing slicing in __getitem__
...m__(self, val):
... print val
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>>> c = C()
>>> c[3]
3
>>> c[3:4]
slice(3, 4, None)
>>> c[3:4:-2]
slice(3, 4, -2)
>>> c[():1j:'a']
slice((), 1j, 'a')
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