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What is the difference between join and merge in Pandas?
...ve some typing by using df1.join(df2) instead.
Some notes on these issues from the documentation at http://pandas.pydata.org/pandas-docs/stable/merging.html#database-style-dataframe-joining-merging:
merge is a function in the pandas namespace, and it is also
available as a DataFrame instance ...
Is there a “do … while” loop in Ruby?
...rs to tell
begin <code> end while <cond>
works differently from
<code> while <cond>
RosettaCode wiki has a similar story:
During November 2005, Yukihiro Matsumoto, the creator of Ruby, regretted this loop feature and suggested using Kernel#loop.
...
Using the Android Application class to persist data
...n (I'd say a total of about 500KB -- is this large for a mobile device?). From what I can tell, any orientation change in the application (in the activity, to be more precise) causes a complete destruction and recreation of the activity. Based on my findings, the Application class does not have th...
How can I get useful error messages in PHP?
...t to make these changes at the .ini file level. Turning on error reporting from within a script is useless, as it won't help with syntax errors or other fatal errors that kill the compile phase. The script gets killed long before it begins executing and reaches the reporting overrides.
...
Force overwrite of local file with what's in origin repo?
...
Full sync has few tasks:
reverting changes
removing new files
get latest from remote repository
git reset HEAD --hard
git clean -f
git pull origin master
Or else, what I prefer is that, I may create a new branch with the latest from the remote using:
git checkout origin/master -b <new branch...
What's the difference between dynamic (C# 4) and var?
...l that happened was that the compiler figured out that s must be a string (from the initializer). In both cases, it knows (in the IL) that s.Length means the (instance) string.Length property.
dynamic is a very different beast; it is most similar to object, but with dynamic dispatch:
dynamic s = "...
Regexp Java for password validation
...e back end that will actually use the password.
I'll start with the regex from the accepted answer:
^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%^&+=])(?=\S+$).{8,}$
First of all, since Java supports \A and \z I prefer to use those to make sure the entire string is validated, independently of...
In Objective-C, what is the equivalent of Java's “instanceof” keyword?
...
From Wikipedia:
In Objective-C, for example, both the
generic Object and NSObject (in
Cocoa/OpenStep) provide the method
isMemberOfClass: which returns true if
the argument to the method is an
instance of the sp...
How much is the overhead of smart pointers compared to normal pointers in C++?
...
My answer is different from the others and i really wonder if they ever profiled code.
shared_ptr has a significant overhead for creation because of it's memory allocation for the control block (which keeps the ref counter and a pointer list to a...
Can you find all classes in a package using reflection?
...is method1 that uses the ClassLoader.
/**
* Scans all classes accessible from the context class loader which belong to the given package and subpackages.
*
* @param packageName The base package
* @return The classes
* @throws ClassNotFoundException
* @throws IOException
*/
private static Cla...