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How to step through Python code to help debug issues?
...es to remember are:
b: set a breakpoint
c: continue debugging until you hit a breakpoint
s: step through the code
n: to go to next line of code
l: list source code for the current file (default: 11 lines including the line being executed)
u: navigate up a stack frame
d: navigate down a stack frame...
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...
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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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 list subtraction operation
...
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):
...
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...
How to add an integer to each element in a list?
...
This talk explains it: Facts and Myths about Python Names and Values: nedbatchelder.com/text/names1.html
– Ned Batchelder
Dec 2 '16 at 13:36
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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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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...