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Modifying a subset of rows in a pandas dataframe
Assume I have a pandas DataFrame with two columns, A and B. I'd like to modify this DataFrame (or create a copy) so that B is always NaN whenever A is 0. How would I achieve that?
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Using Kafka as a (CQRS) Eventstore. Good idea?
... events in the stream. Each Kafka topic consists of one or more partitions and each partition is stored as a directory on the file system. There will also be pressure from ZooKeeper as the number of znodes increases.
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How do I find out which process is locking a file using .NET?
I've seen several of answers about using Handle or Process Monitor , but I would like to be able to find out in my own code (C#)
which process is locking a file.
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Download attachments using Java Mail
Now that I`ve downloaded all the messages, and store them to
4 Answers
4
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What is the dual table in Oracle?
I've heard people referring to this table and was not sure what it was about.
14 Answers
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Multiple inputs with same name through POST in php
Is it possible to get multiple inputs of the same name to post and then access them from PHP? The idea is this: I have a form that allows the entry of an indefinite number of physical addresses along with other information. If I simply gave each of those fields the same name across several entries...
In JavaScript, why is “0” equal to false, but when tested by 'if' it is not false by itself?
...you explicitly do "0" == false, both sides are being converted to numbers, and then the comparison is performed.
When you do: if ("0") console.log("ha"), the string value is being tested. Any non-empty string is true, while an empty string is false.
Equal (==)
If the two operands are not o...
Difference between Key, Primary Key, Unique Key and Index in MySQL
When should I use KEY , PRIMARY KEY , UNIQUE KEY and INDEX ?
8 Answers
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How do I diff the same file between two different commits on the same branch?
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For instance, to see the difference for a file "main.c" between now and two commits back, here are three equivalent commands:
$ git diff HEAD^^ HEAD main.c
$ git diff HEAD^^..HEAD -- main.c
$ git diff HEAD~2 HEAD -- main.c
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is of a type that is invalid for use as a key column in an index
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A unique constraint can't be over 8000 bytes per row and will only use the first 900 bytes even then so the safest maximum size for your keys would be:
create table [misc_info]
(
[id] INTEGER PRIMARY KEY IDENTITY NOT NULL,
[key] nvarchar(450) UNIQUE NOT NULL,
[v...