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How do I declare and initialize an array in Java?
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2737
You can either use array declaration or array literal (but only when you declare and affect the...
When should iteritems() be used instead of items()?
... of iteritems() in all places? Why was iteritems() removed from Python 3? Seems like a terrific and useful method. What's the reasoning behind it?
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Determine device (iPhone, iPod Touch) with iOS
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31 Answers
31
Active
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Are list-comprehensions and functional functions faster than “for loops”?
...in range(10)]`>)
1 0 BUILD_LIST 0
3 LOAD_FAST 0 (.0)
>> 6 FOR_ITER 12 (to 21)
9 STORE_FAST 1 (x)
12 LOAD_FAST 1 (x)
15 LIST_APPEND 2
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Python 3: ImportError “No Module named Setuptools”
I'm having troubles with installing packages in Python 3.
9 Answers
9
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How to find list intersection?
actual output: [1,3,5,6]
expected output: [1,3,5]
11 Answers
11
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Change the color of glyphicons to blue in some- but not at all places using Bootstrap 2
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answered Aug 20 '13 at 12:32
Vikas GhodkeVikas Ghodke
6,29855 gold badges2323 silver badges3737 bronze badges
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How to add a new row to an empty numpy array
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237
The way to "start" the array that you want is:
arr = np.empty((0,3), int)
Which is an empty ...
dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
....drop argument that does just what you asked for:
df = data.frame(a=rep(1:3,4), b=rep(1:2,6))
df$b = factor(df$b, levels=1:3)
df %>%
group_by(b, .drop=FALSE) %>%
summarise(count_a=length(a))
#> # A tibble: 3 x 2
#> b count_a
#> <fct> <int>
#> 1 1 ...