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Determining Referer in PHP

...s the most reliable and secure way to determine what page either sent, or called (via AJAX), the current page. I don't want to use the $_SERVER['HTTP_REFERER'] , because of the (lack of) reliability, and I need the page being called to only come from requests originating on my site. Edit: I am...
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Principal component analysis in Python

... Months later, here's a small class PCA, and a picture: #!/usr/bin/env python """ a small class for Principal Component Analysis Usage: p = PCA( A, fraction=0.90 ) In: A: an array of e.g. 1000 observations x 20 variables, 1000 rows x 20 colum...
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Check if key exists and iterate the JSON array using Python

... If all you want is to check if key exists or not h = {'a': 1} 'b' in h # returns False If you want to check if there is a value for key h.get('b') # returns None Return a default value if actual value is missing h.get('b'...
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One-liner to check whether an iterator yields at least one element?

... Similarly if you need to check if the iterator is empty, one could use all(False for _ in iterator) will check if the iterator is empty. (all returns True if the iterator is empty, otherwise it stops when it sees the first False element) – KGardevoir Apr 3 ...
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How to change the default charset of a MySQL table?

... If you want to change the table default character set and all character columns to a new character set, use a statement like this: ALTER TABLE tbl_name CONVERT TO CHARACTER SET charset_name; So query will be: ALTER TABLE etape_prospection CONVERT TO CHARACTER SET utf8; ...
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PostgreSQL create table if not exists

... CREATE TABLE myschema.mytable (i integer); END IF; END $func$; Call: SELECT create_mytable(); -- call as many times as you want. Notes: The columns schemaname and tablename in pg_tables are case-sensitive. If you double-quote identifiers in the CREATE TABLE statement, you need ...
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Best way to show a loading/progress indicator?

...:18 vwvw 32133 silver badges1212 bronze badges answered Oct 11 '12 at 14:50 Suraj BajajSuraj Bajaj ...
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Shell command to sum integers, one per line?

... just used this for a: count all documents’ pages script: ls $@ | xargs -i pdftk {} dump_data | grep NumberOfPages | awk '{s+=$2} END {print s}' – flying sheep Jul 10 '13 at 14:42 ...
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Downloading images with node.js [closed]

... 32 You can use Axios (a promise-based HTTP client for Node.js) to download images in the order of ...
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Python unittest - opposite of assertRaises?

...the correct solution in fact. The solution proposed by user9876 is conceptually flawed: if you test for the non-raising of say ValueError, but ValueError is instead raised, your test must exit with a failure condition, not an error one. On the other hand, if in running the same code you would raise ...