大约有 47,000 项符合查询结果（耗时：0.0487秒） [XML]
How to filter Pandas dataframe using 'in' and 'not in' like in SQL
...
891
You can use pd.Series.isin.
For "IN" use: something.isin(somewhere)
Or for "NOT IN": ~something....
How can I eliminate slow resolving/loading of localhost/virtualhost (a 2-3 second lag) on Mac OS X L
...nvironments on Mac OS X Lion (brand new macbook air purchased in January 2012), I have noticed that resolving to a virtual host is very slow (around 3 seconds) the first time but after that is fast as long as I continue loading it regularly.
...
Which is better, number(x) or parseFloat(x)?
...
318
The difference between parseFloat and Number
parseFloat/parseInt is for parsing a string, whil...
How to configure PostgreSQL to accept all incoming connections
...
218
Just use 0.0.0.0/0.
host all all 0.0.0.0/0 md5
Make su...
How do I get an object's unqualified (short) class name?
...
184
You can do this with reflection. Specifically, you can use the ReflectionClass::getShortName m...
Is 0 a decimal literal or an octal literal?
...
Yes, 0 is an Octal literal in C++.
As per the C++ Standard:
2.14.2 Integer literals [lex.icon]
integer-literal:
decimal-literal integer-suffixopt
octal-literal integer-suffixopt
hexadecimal-literal integer-suffixopt
decimal-literal:
nonzero-digit
decim...
Pandas percentage of total with groupby
...
14 Answers
14
Active
...
while (1) vs. while(True) — Why is there a difference (in python 2 bytecode)?
Intrigued by this question about infinite loops in perl: while (1) Vs. for (;;) Is there a speed difference? , I decided to run a similar comparison in python. I expected that the compiler would generate the same byte code for while(True): pass and while(1): pass , but this is actually not the c...
Extract elements of list at odd positions
...
Solution
Yes, you can:
l = L[1::2]
And this is all. The result will contain the elements placed on the following positions (0-based, so first element is at position 0, second at 1 etc.):
1, 3, 5
so the result (actual numbers) will be:
2, 4, 6
Exp...
How do the PHP equality (== double equals) and identity (=== triple equals) comparison operators dif
...
11 Answers
11
Active
...