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What exactly do “u” and “r” string flags do, and what are raw string literals?
...d escape sequence (e.g. r"\").
"Raw" is not part of the type, it's merely one way to represent the value. For example, "\\n" and r"\n" are identical values, just like 32, 0x20, and 0b100000 are identical.
You can have unicode raw string literals:
>>> u = ur"\n"
>>> print type(u...
Why use multiple columns as primary keys (composite primary key)
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Your understanding is correct.
You would do this in many cases. One example is in a relationship like OrderHeader and OrderDetail. The PK in OrderHeader might be OrderNumber. The PK in OrderDetail might be OrderNumber AND LineNumber. If it was either of those two, it would not be unique...
Random number generator only generating one random number
...need to write ''two'' lines of code to generate a random number instead of one. Is this really worth it to save reading one simple line of code?
– EMP
Apr 15 '10 at 23:07
5
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What is the rationale for fread/fwrite taking size and count as arguments?
...m) and fread(buf, 1, 1000, stream) is, that in the first case you get only one chunk of 1000 bytes or nuthin, if the file is smaller and in the second case you get everything in the file less than and up to 1000 bytes.
share...
HTML 5: Is it , , or ?
... have your html be well-formed xml, that's it. Of course when transforming one into another you have to make sure it's still valid, but is it worth mentioning? :)
– Michael Krelin - hacker
Dec 22 '09 at 14:37
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How to convert a PNG image to a SVG? [closed]
...e.svg" # PNM to SVG
rm "$File.pnm" # Remove PNM
One-line command
If you want to convert many files, you can also use the following one-line command:
( set -x ; for f_png in *.png ; do f="${f_png%.png}" ; convert "$f_png" "$f.pnm" && potrace "$f.pnm" -s -o "$f.svg...
How can a LEFT OUTER JOIN return more records than exist in the left table?
...e are matches though, it will still return all rows that match, therefore, one row in LEFT that matches two rows in RIGHT will return as two ROWS, just like an INNER JOIN.
EDIT:
In response to your edit, I've just had a further look at your query and it looks like you are only returning data from t...
What is the advantage to using bloom filters?
...ds a chance of existing in your data set. If it doesn't, no extra work is done. No disk reads, etc. (Which you would have to do if it were a hash or tree, etc).
Otherwise, if the filter says "Yes, it's in there", there's a 1% chance that it's wrong, so you do the necessary work to find out. 99% of ...
Check if string ends with one of the strings from a list
What is the pythonic way of writing the following code?
8 Answers
8
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OpenID vs. OAuth [duplicate]
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OpenID is a way to specify one identity for multiple sites so you don't need to register over and over again.
OAuth is a way to allow one application access to one account without giving said application your account login information. You can use th...