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How to check if all of the following items are in a list?
...
Operators like <= in Python are generally not overriden to mean something significantly different than "less than or equal to". It's unusual for the standard library does this--it smells like legacy API to me.
Use the equivalent and more clearly-named method, ...
Set the value of a variable with the result of a command in a Windows batch file
...%a in ('command1 ^| command2') do set VAR=%%a.
– Bill_Stewart
Mar 4 '16 at 19:23
@Bill_Stewart you just saved my day, ...
List comprehension: Returning two (or more) items for each item
...bda x: x + 2
>>> g = lambda x: x ** 2
>>> list(chain.from_iterable((f(x), g(x)) for x in range(3)))
[2, 0, 3, 1, 4, 4]
Timings:
from timeit import timeit
f = lambda x: x + 2
g = lambda x: x ** 2
def fg(x):
yield f(x)
yield g(x)
print timeit(stmt='list(chain.from_itera...
搭建高可用mongodb集群（三）—— 深入副本集内部机制 - 大数据 & AI - 清...
...为1是不显示的，这里标示出来。
rs.conf();
{
"_id" : "rs0",
"version" : 9,
"members" : [
{
"_id" : 0,
"host" : "192.168.1.136:27017" },
{
...
Substitute multiple whitespace with single whitespace in Python [duplicate]
...ce characters that are combined.
To match unicode whitespace:
import re
_RE_COMBINE_WHITESPACE = re.compile(r"\s+")
my_str = _RE_COMBINE_WHITESPACE.sub(" ", my_str).strip()
To match ASCII whitespace only:
import re
_RE_COMBINE_WHITESPACE = re.compile(r"(?a:\s+)")
_RE_STRIP_WHITESPACE = re.co...
Using “label for” on radio buttons
...ds like a clear case to use a checkbox instead :D
– T_D
Mar 13 at 15:16
Ah, no what I meant was one super-label that t...
When to use reinterpret_cast?
...time hence the word static . This is the cast the C++ compiler uses internally for implicit casts also.
11 Answers
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What is the difference between map and flatMap and a good use case for each?
...ark-shell session:
First, some data - two lines of text:
val rdd = sc.parallelize(Seq("Roses are red", "Violets are blue")) // lines
rdd.collect
res0: Array[String] = Array("Roses are red", "Violets are blue")
Now, map transforms an RDD of length N into another RDD of length N.
For examp...
SQL Server: What is the difference between CROSS JOIN and FULL OUTER JOIN?
... cross join produces a cartesian product between the two tables, returning all possible combinations of all rows. It has no on clause because you're just joining everything to everything.
A full outer join is a combination of a left outer and right outer join. It returns all rows in both tables t...
Can you create nested WITH clauses for Common Table Expressions?
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Essentially the post means, that you can't do it, but it is not a big problem.
– peterh - Reinstate Monica
May 30 '17 at 14:40
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