大约有 44,300 项符合查询结果（耗时：0.0372秒） [XML]
Frequency table for a single variable
...s()?
>>> import pandas
>>> my_series = pandas.Series([1,2,2,3,3,3, "fred", 1.8, 1.8])
>>> my_series
0 1
1 2
2 2
3 3
4 3
5 3
6 fred
7 1.8
8 1.8
>>> counts = my_series.value_counts()
>>> counts
3 3
2 ...
Test if number is odd or even
...ession which will return true if $number is even, false if odd:
$number % 2 == 0
Works for every integerPHP value, see as well Arithmetic OperatorsPHP.
Example:
$number = 20;
if ($number % 2 == 0) {
print "It's even";
}
Output:
It's even
...
Error message “Forbidden You don't have permission to access / on this server” [closed]
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665
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What is the difference between Ruby 1.8 and Ruby 1.9
..."cat"[1]
=> 97
{"a","b"} No Longer Supported
Ruby 1.9
irb(main):002:0> {1,2}
SyntaxError: (irb):2: syntax error, unexpected ',', expecting tASSOC
Ruby 1.8.6
irb(main):001:0> {1,2}
=> {1=>2}
Action: Convert to {1 => 2}
Array.to_s Now Contains Punctuation
Ruby 1.9
irb...
how do I work around log4net keeping changing publickeytoken
... which uses a couple of frameworks which is dependent on log4net version 1.2.10.0. Today I tried to include a new framework which is dependent on log4net version 1.2.11.0, I've been stuck ever since:
...
What's the difference between equal?, eql?, ===, and ==?
...
+200
I'm going to heavily quote the Object documentation here, because I think it has some great explanations. I encourage you to read it...
Sorting 1 million 8-decimal-digit numbers with 1 MB of RAM
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720
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How can I force division to be floating point? Division keeps rounding down to 0?
...
In Python 2, division of two ints produces an int. In Python 3, it produces a float. We can get the new behaviour by importing from __future__.
>>> from __future__ import division
>>> a = 4
>>> b = 6
>>...
Java code To convert byte to Hexadecimal
...
byte[] bytes = {-1, 0, 1, 2, 3 };
StringBuilder sb = new StringBuilder();
for (byte b : bytes) {
sb.append(String.format("%02X ", b));
}
System.out.println(sb.toString());
// prints "FF 00 01 02 03 "
See also
java.util....
Are tuples more efficient than lists in Python?
... is much faster than assigning a list.
>>> def a():
... x=[1,2,3,4,5]
... y=x[2]
...
>>> def b():
... x=(1,2,3,4,5)
... y=x[2]
...
>>> import dis
>>> dis.dis(a)
2 0 LOAD_CONST 1 (1)
3 LOAD_CONST ...