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Regular expression to extract text between square brackets
...ollowing regex globally:
\[(.*?)\]
Explanation:
\[ : [ is a meta char and needs to be escaped if you want to match it literally.
(.*?) : match everything in a non-greedy way and capture it.
\] : ] is a meta char and needs to be escaped if you want to match it literally.
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Undo git pull, how to bring repos to old state
...do the merge step, but probably not the fetch (doesn't make a lot of sense and shouldn't be necessary).
To undo the merge, use git reset --hard to reset the local repository to a previous state; use git-reflog to find the SHA-1 of the previous state and then reset to it.
Warning
The commands li...
How to plot two histograms together in R?
I am using R and I have two data frames: carrots and cucumbers. Each data frame has a single numeric column which lists the length of all measured carrots (total: 100k carrots) and cucumbers (total: 50k cucumbers).
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How to pad zeroes to a string?
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Strings:
>>> n = '4'
>>> print(n.zfill(3))
004
And for numbers:
>>> n = 4
>>> print(f'{n:03}') # Preferred method, python >= 3.6
004
>>> print('%03d' % n)
004
>>> print(format(n, '03')) # python >= 2.6
004
>>> print('{0:...
How do I perform an IF…THEN in an SQL SELECT?
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The CASE statement is the closest to IF in SQL and is supported on all versions of SQL Server.
SELECT CAST(
CASE
WHEN Obsolete = 'N' or InStock = 'Y'
THEN 1
ELSE 0
END AS bit) as Saleable,...
Setting the selected value on a Django forms.ChoiceField
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the tuples represent (value, label) pairs for the options and you want to specify the initial value - so the '3' refers to the first item.
– Tom
Oct 29 '17 at 10:19
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How to concatenate properties from multiple JavaScript objects
... many modern browsers but not yet all of them. Use a transpiler like Babel and Traceur to generate backwards-compatible ES5 JavaScript.
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BaseException.message deprecated in Python 2.6
...- almost no coding needed
Just inherit your exception class from Exception and pass the message as the first parameter to the constructor
Example:
class MyException(Exception):
"""My documentation"""
try:
raise MyException('my detailed description')
except MyException as my:
print my # ...
Is std::vector copying the objects with a push_back?
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Yes, std::vector<T>::push_back() creates a copy of the argument and stores it in the vector. If you want to store pointers to objects in your vector, create a std::vector<whatever*> instead of std::vector<whatever>.
However, you need to make sure that the objects referenced...
Portable way to get file size (in bytes) in shell?
...at --format="%s" FILE , but Solaris I have access to doesn't have stat command. What should I use then?
14 Answers
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