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~x + ~y == ~(x + y) is always false?
Does this code always evaluate to false? Both variables are two's complement signed ints.
11 Answers
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add a string prefix to each value in a string column using Pandas
I would like to append a string to the start of each value in a said column of a pandas dataframe (elegantly).
I already figured out how to kind-of do this and I am currently using:
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How do I round to the nearest 0.5?
I have to display ratings and for that i need increments as follows:
9 Answers
9
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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
When using summarise with plyr 's ddply function, empty categories are dropped by default. You can change this behavior by adding .drop = FALSE . However, this doesn't work when using summarise with dplyr . Is there another way to keep empty categories in the result?
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Possible reasons for timeout when trying to access EC2 instance
I cannot SSH into my instance - Operation timed out. What could be the reasons why, and what can I do to resolve it? Rebooting normally takes a long time to take effect, and might just makes things worst
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How to open, read, and write from serial port in C?
I am a little bit confused about reading and writing to a serial port. I have a USB device in Linux that uses the FTDI USB serial device converter driver. When I plug it in, it creates: /dev/ttyUSB1.
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how to find host name from IP with out login to the host
i need to find the host name of a UNIX host whose IP is known with out login to that UNIX host
11 Answers
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ActiveRecord: size vs count
In Rails, you can find the number of records using both Model.size and Model.count . If you're dealing with more complex queries is there any advantage to using one method over the other? How are they different?
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Editing dictionary values in a foreach loop
I am trying to build a pie chart from a dictionary. Before I display the pie chart, I want to tidy up the data. I'm removing any pie slices that would be less than 5% of the pie and putting them in a "Other" pie slice. However I'm getting a Collection was modified; enumeration operation may not exe...
Catching error codes in a shell pipe
I currently have a script that does something like
4 Answers
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