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append new row to old csv file python
I am trying to add a new row to my old csv file. Basically, it gets updated each time I run the Python script.
7 Answers
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How do I calculate the normal vector of a line segment?
Suppose I have a line segment going from (x1,y1) to (x2,y2). How do I calculate the normal vector perpendicular to the line?
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instantiate a class from a variable in PHP?
...you work with namespace, put the current namespace into the string: $var = __NAMESPACE__ . '\\' . $var . 'Class';
– bastey
Sep 2 '13 at 13:28
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Cache Invalidation — Is there a General Solution?
...ched value of b. If you chose 2 you must still check b every time but can fall back on the cache for a if b checks out.
If you layer caches you must consider whether you have violated the 'rules' of the system as a result of the combined behaviour.
If you know that a always has validity if b does...
JavaScript/jQuery to download file via POST with JSON data
...d single-page webapp. It communicates with a RESTful web service via AJAX calls.
14 Answers
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Set Value of Input Using Javascript Function
...g and forgot about the page underneath).
Changing the ID so it was unique allowed me to use the methods listed in Sangeet's answer.
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Why can't code inside unit tests find bundle resources?
... main bundle. I have the following a problem. I am loading a png file. Normally this file is not in the main bundle due the user downloads it from a server. But for a test I want to use a file from the test bundle without copying it into the main bundle.
– Chris
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How to rollback a specific migration?
...nt to go back.
For example:
rake db:rollback STEP=5
Will also rollback all the migration that happened later (4, 3, 2 and also 1).
To roll back all migrations back to (and including) a target migration, use: (This corrected command was added AFTER all the comments pointing out the error in the ...
When creating HTML emails, should we use html, head, body tags?
In my email views, I usually just do something like...
6 Answers
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Why would you use String.Equals over ==? [duplicate]
I recently was introduced to a large codebase and noticed all string comparisons are done using String.Equals() instead of ==
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