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UnboundLocalError on local variable when reassigned after first use
...nd parsing.
Consider how the parse of this line of code works. The lexer reads the source text and breaks it into lexemes, the "smallest components" of the grammar. So when it hits the line
c+=1
it breaks it up into something like
SYMBOL(c) OPERATOR(+=) DIGIT(1)
The parser eventually wants ...
AWS MySQL RDS vs AWS DynamoDB [closed]
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You can read AWS explanation about it here.
In short, if you have mainly Lookup queries (and not Join queries), DynamoDB (and other NoSQL DB) is better. If you need to handle a lot of data, you will be limited when using MySQL (and ...
Why are there no ++ and -- operators in Python?
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I see the much bigger concern being readability and predictability. Back in my C days, I saw more than enough bugs stemming from misunderstandings about the distinction between i++ and ++i...
– Charles Duffy
Jul 17 '13 at ...
Why not use HTTPS for everything?
...swered May 1 '10 at 0:36
EadwacerEadwacer
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Command copy exited with code 4 when building - Visual Studio restart solves it
... and then when I build my solution here (with 7 projects in it) I get the dreaded 'Command copy exited with code 4' error, in Visual Studio 2010 Premium ed.
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Explaining Apache ZooKeeper
... for coordination, where messages are exchanged between the clients.
How reads are handled
This is where ZooKeeper excels: reads are concurrent since they are served by the specific server that the client connects to. However, this is also the reason for the eventual consistency: the "view" of a ...
How to read the Stock CPU Usage data
...do NOT reperesent load average in %:
http://forum.xda-developers.com/showthread.php?t=1495763
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Why is i++ not atomic?
... which uses the ll and sc: load-linked, and store-conditional. Load-linked reads the word, and store-conditional stores the new value if the word has not changed, or else it fails (which is detected and causes a re-try).
sha...
Parse a .py file, read the AST, modify it, then write back the modified source code
I want to programmatically edit python source code. Basically I want to read a .py file, generate the AST , and then write back the modified python source code (i.e. another .py file).
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How do ACID and database transactions work?
...d data will ever be violated.
Isolation means that one transaction cannot read data from another transaction that is not yet completed. If two transactions are executing concurrently, each one will see the world as if they were executing sequentially, and if one needs to read data that is written b...