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Pandas every nth row
...use to get the nth data or drop the nth row is the following:
df1 = df[df.index % 3 != 0] # Excludes every 3rd row starting from 0
df2 = df[df.index % 3 == 0] # Selects every 3rd raw starting from 0
This arithmetic based sampling has the ability to enable even more complex row-selections.
This...
How do I uniquely identify computers visiting my web site?
..., fingerprints changed quite
rapidly, but even a simple heuristic was usually able to guess when a fingerprint was an “upgraded” version of a previously observed browser’s
fingerprint, with 99.1% of guesses correct and a false positive rate of only
0.86%.
We discuss what privacy thr...
PHP + MySQL transactions examples
I really haven't found normal example of PHP file where MySQL transactions are being used. Can you show me simple example of that?
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Python Dictionary Comprehension
...1)
x_s = range(1, 11)
# x_s = range(11, 1, -1) # Also works
d = dict([(i_s[index], x_s[index], ) for index in range(len(i_s))])
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New Array from Index Range Swift
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Pretty-Printing JSON with PHP
...HP 5.4 offers the JSON_PRETTY_PRINT option for use with the json_encode() call.
http://php.net/manual/en/function.json-encode.php
<?php
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$json_string = json_encode($data, JSON_PRETTY_PRINT);
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Fastest way to check if a string is JSON in PHP?
I need a really, really fast method of checking if a string is JSON or not. I feel like this is not the best way:
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Avoid duplicates in INSERT INTO SELECT query in SQL Server
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Not totally true. When you create a unique index, you can set it to "ignore duplicates", in which case SQL Server will ignore any attempts to add a duplicate.
– IamIC
Dec 11 '10 at 8:23
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How to get a string after a specific substring?
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s1 = "hello python world , i'm a beginner "
s2 = "world"
print s1[s1.index(s2) + len(s2):]
If you want to deal with the case where s2 is not present in s1, then use s1.find(s2) as opposed to index. If the return value of that call is -1, then s2 is not in s1.
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Can't use method return value in write context
... functions.
However, the real problem you have is that you use empty() at all, mistakenly believing that "empty" value is any different from "false".
Empty is just an alias for !isset($thing) || !$thing. When the thing you're checking always exists (in PHP results of function calls always exist), ...