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Python list subtraction operation
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Use a list comprehension:
[item for item in x if item not in y]
If you want to use the - infix syntax, you can just do:
class MyList(list):
def __init__(self, *args):
super(MyList, self).__init__(args)
def __sub__(self, other):
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Code Golf: Lasers
...board where $t{99*i+j} holds the character at row i,column j. Then,
%d=split//,'>.^1<2v3' ; ($r)=grep{$d|=$d{$t{$_}}}%t
it searches the elements of %t for a character that matches > ^ < or v, and simultaneously sets $d to a value between 0 and 3 that indicates the initial direction of...
Timeout a command in bash without unnecessary delay
...cripts/timeout3
#!/bin/bash
#
# The Bash shell script executes a command with a time-out.
# Upon time-out expiration SIGTERM (15) is sent to the process. If the signal
# is blocked, then the subsequent SIGKILL (9) terminates it.
#
# Based on the Bash documentation example.
# Hello Chet,
# please f...
Python - Create a list with initial capacity
...ge the duration)
simple append 0.0102
pre-allocate 0.0098
Conclusion. It barely matters.
Premature optimization is the root of all evil.
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If table exists drop table then create it, if it does not exist just create it
...e`; before your CREATE TABLE statement.
That statement drops the table if it exists but will not throw an error if it does not.
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What is the difference between a mutable and immutable string in C#?
..."cannot change" respectively. The meaning of the words is the same in the IT context; i.e.
a mutable string can be changed, and
an immutable string cannot be changed.
The meanings of these words are the same in C# / .NET as in other programming languages / environments, though (obviously) the n...
Starting python debugger automatically on error
This is a question I have wondered about for quite some time, yet I have never found a suitable solution. If I run a script and I come across, let's say an IndexError, python prints the line, location and quick description of the error and exits. Is it possible to automatically start pdb when an err...
How to make an array of arrays in Java
... point of the variable declaration, whereas the shorter syntax only works with declarations.)
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How do I get Pyflakes to ignore a statement?
A lot of our modules start with:
7 Answers
7
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Map over object preserving keys
The map function in underscore.js, if called with a javascript object, returns an array of values mapped from the object's values.
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