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How do I append one string to another in Python?
...e.g.
s = ""
for i in range(n):
s+=str(i)
used to be O(n^2), but now it is O(n).
From the source (bytesobject.c):
void
PyBytes_ConcatAndDel(register PyObject **pv, register PyObject *w)
{
PyBytes_Concat(pv, w);
Py_XDECREF(w);
}
/* The following function breaks the notion that strin...
Return None if Dictionary key is not available
I need a way to get a dictionary value if its key exists, or simply return None , if it does not.
11 Answers
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Maximum and Minimum values for ints
..., which is the maximum value representable by a signed word. Equivalently, it's the size of the largest possible list or in-memory sequence.
Generally, the maximum value representable by an unsigned word will be sys.maxsize * 2 + 1, and the number of bits in a word will be math.log2(sys.maxsize * 2...
What's the difference between window.location and document.location in JavaScript?
...
According to the W3C, they are the same. In reality, for cross browser safety, you should use window.location rather than document.location.
See: http://www.w3.org/TR/html/browsers.html#dom-location
...
Make an Installation program for C# applications and include .NET Framework installer into the setup
I've finished my C# application, but I have a little problem:
4 Answers
4
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What can I do to resolve a “Row not found or changed” Exception in LINQ to SQL on a SQL Server Compa
When executing SubmitChanges to the DataContext after updating a couple properties with a LINQ to SQL connection (against SQL Server Compact Edition) I get a "Row not found or changed." ChangeConflictException.
...
How to create streams from string in Node.Js?
I am using a library, ya-csv , that expects either a file or a stream as input, but I have a string.
11 Answers
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C++11 rvalues and move semantics confusion (return statement)
... returns a temporary which is caught by rval_ref. That temporary will have its life extended beyond the rval_ref definition and you can use it as if you had caught it by value. This is very similar to the following:
const std::vector<int>& rval_ref = return_vector();
except that in my re...
What's the idiomatic syntax for prepending to a short python list?
...
The s.insert(0, x) form is the most common.
Whenever you see it though, it may be time to consider using a collections.deque instead of a list.
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Check if a string matches a regex in Bash script
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You can use the test construct, [[ ]], along with the regular expression match operator, =~, to check if a string matches a regex pattern.
For your specific case, you can write:
[[ $date =~ ^[0-9]{8}$ ]] && echo "yes"
Or more a accurate test:
[[ $date =~ ^[0-9]{...