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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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Creating a zero-filled pandas data frame
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answered Apr 9 '14 at 13:49
ShravanShravan
1,86322 gold badges1212 silver badges1919 bronze badges
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Python String and Integer concatenation [duplicate]
...kticks) is deprecated in later versions of Python 2, and removed in Python 3. Use the str() function instead.
You can use :
string = 'string'
for i in range(11):
string +=`i`
print string
It will print string012345678910.
To get string0, string1 ..... string10 you can use this as @YOU suggeste...
Dynamically select data frame columns using $ and a character value
... a reproducible example below:
# set seed for reproducibility
set.seed(123)
df <- data.frame( col1 = sample(5,10,repl=T) , col2 = sample(5,10,repl=T) , col3 = sample(5,10,repl=T) )
# We want to sort by 'col3' then by 'col1'
sort_list <- c("col3","col1")
# Use 'do.call' to call order. Sec...
What are 'get' and 'set' in Swift?
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38
That's actually explained right before the code:
In addition to simple properties that are sto...
List of lists into numpy array
...answer of Ignacio Vazquez-Abrams will not work. Instead there are at least 3 options:
1) Make an array of arrays:
x=[[1,2],[1,2,3],[1]]
y=numpy.array([numpy.array(xi) for xi in x])
type(y)
>>><type 'numpy.ndarray'>
type(y[0])
>>><type 'numpy.ndarray'>
2) Make an arr...
Python: changing value in a tuple
...via:
t = ('275', '54000', '0.0', '5000.0', '0.0')
lst = list(t)
lst[0] = '300'
t = tuple(lst)
But if you're going to need to change things, you probably are better off keeping it as a list
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Is there a 'foreach' function in Python 3?
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user 451
35255 silver badges88 bronze badges
answered Aug 18 '13 at 0:33
Jo Are ByJo Are By
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Small Haskell program compiled with GHC into huge binary
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Let's see what's going on, try
$ du -hs A
13M A
$ file A
A: ELF 64-bit LSB executable, x86-64, version 1 (SYSV),
dynamically linked (uses shared libs), for GNU/Linux 2.6.27, not stripped
$ ldd A
linux-vdso.so.1 => (0x00007fff1b9ff000)
libXr...
Python multiprocessing pool.map for multiple arguments
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388
The answer to this is version- and situation-dependent. The most general answer for recent ver...