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pandas three-way joining multiple dataframes on columns

...ve some common column, like name in your example, I'd do the following: df_final = reduce(lambda left,right: pd.merge(left,right,on='name'), dfs) That way, your code should work with whatever number of dataframes you want to merge. Edit August 1, 2016: For those using Python 3: reduce has been m...
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ImportError: No module named pip

... After installing ez_setup, you should have easy_install available. To install pip just do: easy_install pip share | improve this answer ...
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Mac zip compress without __MACOSX folder?

... built in zip compressor in Mac OSX, it results in an extra folder titled "__MACOSX" created in the extracted zip. 13 Answe...
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What is the difference between typeof and instanceof and when should one be used vs. the other?

...ot work as expected and typeof works well ... developer.mozilla.org/En/Core_JavaScript_1.5_Reference/… – farinspace May 22 '09 at 19:37 55 ...
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How do you produce a .d.ts “typings” definition file from an existing JavaScript library?

... change all the extensions to .ts. Get-ChildItem | foreach { Rename-Item $_ $_.Name.Replace(".js", ".ts") } Second, use the TypeScript compiler to generate definition files. There will be a bunch of compiler errors, but we can ignore those. Get-ChildItem | foreach { tsc $_.Name } Finally, com...
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How to implement the factory method pattern in C++ correctly

...ude <memory> class FactoryReleaseOwnership{ public: std::unique_ptr<Foo> createFooInSomeWay(){ return std::unique_ptr<Foo>(new Foo(some, args)); } }; // Factory retains object ownership // Thus returning a reference. #include <boost/ptr_container/ptr_vector.hpp&...
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Ways to implement data versioning in MongoDB

...nt contain a dictionary of time-stamped diffs. Something like this: { _id : "id of address book record", changes : { 1234567 : { "city" : "Omaha", "state" : "Nebraska" }, 1234568 : { "city" : "Kansas City", "state" : "Missouri" } } } To make...
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module.exports vs exports in Node.js

... Setting module.exports allows the database_module function to be called like a function when required. Simply setting exports wouldn't allow the function to be exported because node exports the object module.exports references. The following code wouldn't allow the...
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How to find out what group a given user has?

... done|sed s/\:/\,/g|tr -d ' '|sed -e "s/^/$HOSTNAME,/"> /tmp/"$HOSTNAME"_inventory.txt sudo cat /etc/sudoers| grep -v "^#"|awk '{print $1}'|grep -v Defaults|sed '/^$/d;s/[[:blank:]]//g'>/tmp/"$HOSTNAME"_sudo.txt paste -d , /tmp/"$HOSTNAME"_inventory.txt /tmp/"$HOSTNAME"_sudo.txt|sed 's/,[[:b...
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Iterate keys in a C++ map

...te on the keys instead of the pairs), then take a look at Boost's transform_iterator. [Tip: when looking at Boost documentation for a new class, read the "examples" at the end first. You then have a sporting chance of figuring out what on earth the rest of it is talking about :-)] ...