大约有 46,000 项符合查询结果（耗时：0.0411秒） [XML]
How to validate an email address using a regular expression?
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+50
The fully RFC 822 compliant regex is inefficient and obscure because of its length. Fortunately, RFC 822 was superseded twice and the...
How to check BLAS/LAPACK linkage in NumPy and SciPy?
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edited Dec 16 '19 at 11:30
Demi-Lune
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answered O...
Why is address zero used for the null pointer?
...s a pointer with the value zero if it can't get me memory; I use if (p != 0) all the time to make sure passed pointers are valid, etc.
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What do “branch”, “tag” and “trunk” mean in Subversion repositories?
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answered Aug 19 '08 at 13:35
Jon LimjapJon Limjap
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How to grant remote access to MySQL for a whole subnet?
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edited Nov 14 '17 at 20:33
answered Jul 31 '12 at 15:01
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How to form tuple column from two columns in Pandas
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208
Get comfortable with zip. It comes in handy when dealing with column data.
df['new_col'] = li...
Why do Lua arrays(tables) start at 1 instead of 0?
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Although I too found them weird at the beginning, I have learned to love 0-based arrays. But I get by OK with Lua's 1-based arrays, especially by
using Lua's generic for loop and the ipairs operator—I can usually avoid worrying about just how arrays are indexed.
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plot a circle with pyplot
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205
You need to add it to an axes. A Circle is a subclass of an Artist, and an axes has an add_arti...
What's the difference between a single precision and double precision floating point operation?
...entation requires a 32 bit word, which may be represented as numbered from 0 to 31, left to right.
The first bit is the sign bit, S,
the next eight bits are the exponent bits, 'E', and
the final 23 bits are the fraction 'F':
S EEEEEEEE FFFFFFFFFFFFFFFFFFFFFFF
0 1 8 9 3...
How is “int* ptr = int()” value initialization not illegal?
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110
int() is a constant expression with a value of 0, so it's a valid way of producing a null pointe...