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How do you delete a column by name in data.table?
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Any of the following will remove column foo from the data.table df3:
# Method 1 (and preferred as it takes 0.00s even on a 20GB data.table)
df3[,foo:=NULL]
df3[, c("foo","bar"):=NULL] # remove two columns
myVar = "foo"
df3[, (myVar):=NULL] # lookup myVar contents
# Method 2a -- A saf...
Extracting .jar file with command line
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153
From the docs:
To extract the files from a jar file, use x, as in:
C:\Java> jar xf myFil...
Replace a value if null or undefined in JavaScript
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edited Apr 15 '13 at 12:56
MojoFilter
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How to use 'find' to search for files created on a specific date? [closed]
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328
As pointed out by Max, you can't, but checking files modified or accessed is not all that hard...
Hash Map in Python
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253
Python dictionary is a built-in type that supports key-value pairs.
streetno = {"1": "Sachin Te...
How do I add files and folders into GitHub repos?
...acing a problem with adding files. I have added readme.txt . Also, I have 3 other PHP files and a folder including images.
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How do I find the time difference between two datetime objects in python?
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388
>>> import datetime
>>> first_time = datetime.datetime.now()
>>> la...
Converting a string to a date in JavaScript
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33 Answers
33
Active
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How do I get an ISO 8601 date on iOS?
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213
Use NSDateFormatter:
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
NSLoca...
Get event listeners attached to node using addEventListener
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answered Mar 27 '13 at 18:13
NVINVI
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