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SQL RANK() versus ROW_NUMBER()
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answered Oct 12 '11 at 22:38
Ritesh MengjiRitesh Mengji
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Maven 3 warnings about build.plugins.plugin.version
Since I updated to Maven 3 I get the following warning messages at each build :
7 Answers
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Single Line Nested For Loops
...f the list comprehension (here (x,y)):
>>> [(x, y) for x in [1,2,3] for y in [3,1,4] if x != y]
[(1, 3), (1, 4), (2, 3), (2, 1), (2, 4), (3, 1), (3, 4)]
It's exactly the same as this nested for loop (and, as the tutorial says, note how the order of for and if are the same).
>>>...
Reorder levels of a factor without changing order of values
...f <- data.frame(f = 1:4, g = letters[1:4])
df
# f g
# 1 1 a
# 2 2 b
# 3 3 c
# 4 4 d
levels(df$g)
# [1] "a" "b" "c" "d"
df$g <- factor(df$g, levels = letters[4:1])
# levels(df$g)
# [1] "d" "c" "b" "a"
df
# f g
# 1 1 a
# 2 2 b
# 3 3 c
# 4 4 d
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“cannot resolve symbol R” in Android Studio
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What does the “map” method do in Ruby?
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432
The map method takes an enumerable object and a block, and runs the block for each element, out...
Selecting pandas column by location
... mind:
>>> df
A B C D
0 0.424634 1.716633 0.282734 2.086944
1 -1.325816 2.056277 2.583704 -0.776403
2 1.457809 -0.407279 -1.560583 -1.316246
3 -0.757134 -1.321025 1.325853 -2.513373
4 1.366180 -1.265185 -2.184617 0.881514
>>> df.iloc[:, ...
How to set Python's default version to 3.x on OS X?
...tain Lion and the basic default Python version is 2.7. I downloaded Python 3.3 and want to set it as default.
21 Answers
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What's the u prefix in a Python string?
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You're right, see 3.1.3. Unicode Strings.
It's been the syntax since Python 2.0.
Python 3 made them redundant, as the default string type is Unicode. Versions 3.0 through 3.2 removed them, but they were re-added in 3.3+ for compatibility wi...
Integrate ZXing in Android Studio
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I was integrating ZXING into an Android application and there were no good sources for the inpu...