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Python Pandas merge only certain columns
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You can use .loc to select the specific columns with all rows and then pull that. An example is below:
pandas.merge(dataframe1, dataframe2.iloc[:, [0:5]], how='left', on='key')
In this example, you are merging dataframe1 and dataframe2. You have chosen to do an outer left jo...
Floating point vs integer calculations on modern hardware
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From my experience, there are many, many variables to performance...especially between integer & floating point math. It varies strongly from processor to processor (even within the same family such as x86) because different processors have different "pipeline" lengths. Also, some operations ...
How to upload a file in Django? [closed]
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Phew, Django documentation really does not have good example about this. I spent over 2 hours to dig up all the pieces to understand how this works. With that knowledge I implemented a project that makes possible to upload files and show them as list. To...
Error: Jump to case label
...code, if foo equals 1, everything is ok, but if it equals 2, we'll accidentally use the i variable which does exist but probably contains garbage.
switch(foo) {
case 1:
int i = 42; // i exists all the way to the end of the switch
dostuff(i);
break;
case 2:
dostuff(i*2); // i is ...
mongodb count num of distinct values per field/key
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expertexpert
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Python: One Try Multiple Except
...n) as e:
handle_either_of_3rd_4th_or_5th()
except Exception:
handle_all_other_exceptions()
See: http://docs.python.org/tutorial/errors.html
The "as" keyword is used to assign the error to a variable so that the error can be investigated more thoroughly later on in the code. Also note that...
What is the Java equivalent of PHP var_dump?
...for free. It is done with convention rather than language constructs. In all data transfer classes (and maybe even in all classes you write...), you should implement a sensible toString method. So here you need to override toString() in your Person class and return the desired state.
There are u...
Generating Guids in Ruby
I have problem that is really easily solved with Guids.
10 Answers
10
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How do I raise the same Exception with a custom message in Python?
...ssign a special meaning to the elements of this tuple, while others are usually called only with a single string giving an error message.". So the code won't work arg[0] is not an error message (it could be an int, or it could be a string representing a file name).
– Trent
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Keyboard shortcuts in WPF
I know about using _ instead of & , but I'm looking at all the Ctrl + type shortcuts.
10 Answers
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