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How to get the last N rows of a pandas DataFrame?
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Don't forget DataFrame.tail! e.g. df1.tail(10)
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Rails: around_* callbacks
...t understand when the around_* callbacks are triggered in relation to before_* and after_* .
2 Answers
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Regular expression to allow spaces between words
...ows letters and numbers. The regex below works great, but it doesn't allow for spaces between words.
15 Answers
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What's the need of array with zero elements?
...ered a hack (as Aniket said), but it was standardized in C99. The standard format for it now is:
struct bts_action {
u16 type;
u16 size;
u8 data[];
} __attribute__ ((packed)); /* Note: the __attribute__ is irrelevant here */
Note that you don't mention any size for the data field. ...
Algorithm to detect corners of paper sheet in photo
...orners of an invoice/receipt/sheet-of-paper in a photo? This is to be used for subsequent perspective correction, before OCR.
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How to read and write INI file with Python3?
...config.set('section_b', 'not_found_val', str(404))" because the parameters for "set" have to be strings. Excellent example, thanks!
– Mr Ed
Dec 29 '18 at 13:42
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Conveniently Declaring Compile-Time Strings in C++
...header) – though this is true of most macroless solutions thanks to the aforementioned constexpr compromise – and the range checking doesn't impress me much because even the lowly constexpr const char * has that. I rolled my own parameter pack string, which can also be made from a literal (using...
How do I get the result of a command in a variable in windows?
...n a Windows batch script (see how to get the result of a command in bash for the bash scripting equivalent). A solution that will work in a .bat file is preferred, but other common windows scripting solutions are also welcome.
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When is assembly faster than C?
One of the stated reasons for knowing assembler is that, on occasion, it can be employed to write code that will be more performant than writing that code in a higher-level language, C in particular. However, I've also heard it stated many times that although that's not entirely false, the cases wh...
What __init__ and self do on Python?
...sents a constructor in Python. When you call A() Python creates an object for you, and passes it as the first parameter to the __init__ method. Any additional parameters (e.g., A(24, 'Hello')) will also get passed as arguments--in this case causing an exception to be raised, since the constructor ...