大约有 47,000 项符合查询结果（耗时：0.0888秒） [XML]
Adding new column to existing DataFrame in Python pandas
I have the following indexed DataFrame with named columns and rows not- continuous numbers:
24 Answers
...
unit testing of private functions with mocha and node.js
...alled by test code outside the module. That's due to how JavaScript works, and Mocha cannot by itself circumvent this.
In the few instances where I determined that testing a private function is the right thing to do, what I've done is set some environment variable that my module checks to determine...
How do I use a Boolean in Python?
...
Actually Python didn't have a boolean type for a long time (as in old C), and some programmers still use integers instead of booleans.
share
|
improve this answer
|
follow
...
In Java, how do I convert a byte array to a string of hex digits while keeping leading zeros? [dupli
...oach would be to check how many digits are output by Integer.toHexString() and add a leading zero to each byte if needed. Something like this:
public static String toHexString(byte[] bytes) {
StringBuilder hexString = new StringBuilder();
for (int i = 0; i < bytes.length; i++) {
...
What does ||= (or-equals) mean in Ruby?
...
This question has been discussed so often on the Ruby mailing-lists and Ruby blogs that there are now even threads on the Ruby mailing-list whose only purpose is to collect links to all the other threads on the Ruby mailing-list that discuss this issue.
Here's one: The definitive list of ||= ...
What does (x ^ 0x1) != 0 mean?
...expression is false if x == 1.
So the test is the same as:
if (x != 1)
and is therefore (arguably) unnecessarily obfuscated.
share
|
improve this answer
|
follow
...
Difference between binary tree and binary search tree
Can anyone please explain the difference between binary tree and binary search tree with an example ?
12 Answers
...
In practice, what are the main uses for the new “yield from” syntax in Python 3.3?
...ld from is all about. Because, let's face it, if all yield from does is expand the for loop, then it does not warrant adding yield from to the language and preclude a whole bunch of new features from being implemented in Python 2.x.
What yield from does is it establishes a transparent bidirectional...
Need a simple explanation of the inject method
...umulator: the result of each run of the block is stored in the accumulator and then passed to the next execution of the block. In the case of the code shown above, you are defaulting the accumulator, result, to 0. Each run of the block adds the given number to the current total and then stores the r...
How to format time since xxx e.g. “4 minutes ago” similar to Stack Exchange sites
...answered Jul 5 '10 at 7:45
Sky SandersSky Sanders
32k55 gold badges6161 silver badges8686 bronze badges
...