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how do you filter pandas dataframes by multiple columns
To filter a dataframe (df) by a single column, if we consider data with male and females we might:
6 Answers
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How to get element by classname or id
I am trying to find the element in html by angularjs.
4 Answers
4
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Precise Financial Calculation in JavaScript. What Are the Gotchas?
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You should probably scale your decimal values by 100, and represent all the monetary values in whole cents. This is to avoid problems with floating-point logic and arithmetic. There is no decimal data type in JavaScript - the only numeric data type is floating-point. The...
Can you write virtual functions / methods in Java?
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From wikipedia
In Java, all non-static methods are by
default "virtual functions." Only
methods marked with the keyword final,
which cannot be overridden, along with
private methods, which are not
inherited, are non-virtual.
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Private vs Protected - Visibility Good-Practice Concern [closed]
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Let me preface this by saying I'm talking primarily about method access here, and to a slightly lesser extent, marking classes final, not member access.
The old wisdom
"mark it private unless you have a good reason not to"
made sense in days w...
Do sessions really violate RESTfulness?
... header instead of the Authorization or some other
proprietary header.
By session cookies you store the client state on the server and so your request has a context. Let's try to add a load balancer and another service instance to your system. In this case you have to share the sessions between ...
Any reason to write the “private” keyword in C#?
...I don't write public , protected , internal , etc. it will be private by default). (Please correct me if I am wrong.)
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Reference assignment operator in PHP, =&
... to another, instead of copying the existing data.
It's called assignment by reference, which, to quote the manual, "means that both variables end up pointing at the same data, and nothing is copied anywhere".
The only thing that is deprecated with =& is "assigning the result of new by referen...
What is the difference between ports 465 and 587?
...outgoing connections to SMTP port (port 25).
SSL encryption may be started by STARTTLS command at SMTP level if server supports it and your ISP does not filter server's EHLO reply (reported 2014).
Port 25 is used by MTA to MTA communication (mail server to mail server). It may be used for client ...
ssh “permissions are too open” error
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Keys need to be only readable by you:
chmod 400 ~/.ssh/id_rsa
If Keys need to be read-writable by you:
chmod 600 ~/.ssh/id_rsa
600 appears to be fine as well (in fact better in most cases, because you don't need to change file permissions later to e...