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Add column with constant value to pandas dataframe [duplicate]
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The reason this puts NaN into a column is because df.index and the Index of your right-hand-side object are different. @zach shows the proper way to assign a new column of zeros. In general, pandas tries to do as much alignment of indices as possible. One downside is that when indice...
What's the dSYM and how to use it? (iOS SDK)
...es. I guess this is a debugging related file, but I don't know what it is, and how to use it.
2 Answers
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Creating an R dataframe row-by-row
...d like to construct a dataframe row-by-row in R. I've done some searching, and all I came up with is the suggestion to create an empty list, keep a list index scalar, then each time add to the list a single-row dataframe and advance the list index by one. Finally, do.call(rbind,) on the list.
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Rails: How to change the title of a page?
...;/h1>
</body>
It's also possible to encapsulate the content_for and yield(:title) statements in helper methods (as others have already suggested). However, in simple cases such as this one I like to put the necessary code directly into the specific views without custom helpers.
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git submodule tracking latest
We are moving our (huge) project to git and we are thinking about using submodules. Our plan is to have three different heads in the superproject: release,stable,latest. The project leads will handle the release and stable branches. They will move the submodules as required.
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Run Cron job every N minutes plus offset
...on
An * in the minute field is the same as 0-59/1 where 0-59 is the range and 1 is the step. The command will run at the first minute in the range (0), then at all successive minutes that are distant from the first by step (1), until the last (59).
Which is why */20 * * * * will run at 0 minutes, ...
How to check what user php is running as?
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If available you can probe the current user account with posix_geteuid and then get the user name with posix_getpwuid.
$username = posix_getpwuid(posix_geteuid())['name'];
If you are running in safe mode however (which is often the case when exec is disabled), then it's unlikely that your PH...
Copying files using rsync from remote server to local machine
Once I've ssh'd into my remote server, what would the command be to copy all files from a directory to a local directory on my machine?
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Use PPK file in Mac Terminal to connect to remote connection over SSH [closed]
I have been using Putty on Windows XP and used the .ppk file to connect to my Linux servers (several servers).
3 Answers
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Mysql: Select rows from a table that are not in another
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If you have 300 columns as you mentioned in another comment, and you want to compare on all columns (assuming the columns are all the same name), you can use a NATURAL LEFT JOIN to implicitly join on all matching column names between the two tables so that you don't have to tediously t...