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“Unicode Error ”unicodeescape" codec can't decode bytes… Cannot open text files in Python 3 [duplica
...owed by the character 's', which is invalid.
You either need to duplicate all backslashes:
"C:\\Users\\Eric\\Desktop\\beeline.txt"
Or prefix the string with r (to produce a raw string):
r"C:\Users\Eric\Desktop\beeline.txt"
...
Retrieve only the queried element in an object array in MongoDB collection
...r to filter an array during projection, which has the benefit of including all matches, instead of just the first one.
db.test.aggregate([
// Get just the docs that contain a shapes element where color is 'red'
{$match: {'shapes.color': 'red'}},
{$project: {
shapes: {$filter: {
...
What does the 'u' symbol mean in front of string values? [duplicate]
Yes in short i would like to know why am I seeing a u in front of my keys and values.
2 Answers
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Iterating over Java collections in Scala
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As of Scala 2.8, all you have to do is to import the JavaConversions object, which already declares the appropriate conversions.
import scala.collection.JavaConversions._
This won't work in previous versions though.
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Using module 'subprocess' with timeout
...that contains command's merged stdout, stderr data.
check_output raises CalledProcessError on non-zero exit status as specified in the question's text unlike proc.communicate() method.
I've removed shell=True because it is often used unnecessarily. You can always add it back if cmd indeed requir...
sizeof single struct member in C
... char text[member_size(Parent, text)];
int used;
} Child;
I'm actually a bit surprised that sizeof((type *)0)->member) is even allowed as a constant expression. Cool stuff.
share
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impr...
What's the proper way to install pip, virtualenv, and distribute for Python?
...estion 4314376 , I recommended using ez_setup so that you could then install pip and virtualenv as follows:
15 Answer...
/usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.15' not found
...
I'm compiling gcc 4.6 from source, and apparently
sudo make install
didn't catch this one. I dug around and found
gcc/trunk/x86_64-unknown-linux-gnu/libstdc++-v3/src/.libs/libstdc++.so.6.0.15
I copied it in to /usr/lib and redirected libstdc++.so.6 to point to the new one, and now e...
Why is iterating through a large Django QuerySet consuming massive amounts of memory?
...rst time you iterate over it. For example, this will print the headline of all entries in the database:
for e in Entry.objects.all():
print e.headline
So your ten million rows are retrieved, all at once, when you first enter that loop and get the iterating form of the queryset. The wait ...
What is the difference between Θ(n) and O(n)?
...e of the algorithm as n gets larger is at most proportional to g(n).
Normally, even when people talk about O(g(n)) they actually mean Θ(g(n)) but technically, there is a difference.
More technically:
O(n) represents upper bound. Θ(n) means tight bound.
Ω(n) represents lower bound.
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