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Concatenate a vector of strings/character
...ta, collapse = '')
Thanks to http://twitter.com/onelinetips/status/7491806343
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warning: implicit declaration of function
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236
You are using a function for which the compiler has not seen a declaration ("prototype") yet.
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File extension for PowerShell 3
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133
PowerShell files for all versions are .ps1 (or .psm1, .psd1, etc.).
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Custom Python list sorting
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edited Feb 5 '15 at 17:33
Charlie
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answered Aug 7 '12 at 16:...
Rails 3 execute custom sql query without a model
...t that is supposed to deal with database. I used code given below in rails 3
5 Answers
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What does the caret operator (^) in Python do?
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>>> 0^1
1
To explain one of your own examples:
>>> 8^3
11
Think about it this way:
1000 # 8 (binary)
0011 # 3 (binary)
---- # APPLY XOR ('vertically')
1011 # result = 11 (binary)
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Specify custom Date format for colClasses argument in read.table/read.csv
...rom) as.Date(from, format="%d/%m/%Y") )
tmp <- c("1, 15/08/2008", "2, 23/05/2010")
con <- textConnection(tmp)
tmp2 <- read.csv(con, colClasses=c('numeric','myDate'), header=FALSE)
str(tmp2)
Then modify if needed to work for your data.
Edit ---
You might want to run setClass('myDate') ...
How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly
I have a dataframe with ~300K rows and ~40 columns.
I want to find out if any rows contain null values - and put these 'null'-rows into a separate dataframe so that I could explore them easily.
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