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When I catch an exception, how do I get the type, file, and line number?
...Error:
print(traceback.format_exc())
Output
Traceback (most recent call last):
File "/path/to/file.py", line 51, in <module>
print(4/0)
ZeroDivisionError: division by zero
Process finished with exit code 0
...
Sell me on const correctness
...ll, using const is good practice because...
It protects you from accidentally changing variables that aren't intended be changed,
It protects you from making accidental variable assignments, and
The compiler can optimize it. For instance, you are protected from
if( x = y ) // whoops, meant if(...
Does use of final keyword in Java improve the performance?
...
Usually not. For virtual methods, HotSpot keeps track of whether the method has actually been overridden, and is able to perform optimizations such as inlining on the assumption that a method hasn't been overridden - until it lo...
What is the size of an enum in C?
...set of enum values, but I need each enum value to be 64 bits wide. If I recall correctly, an enum is generally the same size as an int; but I thought I read somewhere that (at least in GCC) the compiler can make the enum any width they need to be to hold their values. So, is it possible to have an e...
Using the “final” modifier whenever applicable in Java [closed]
...ce of declaring every variable (local or class), parameter final if they really are.
25 Answers
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'id' is a bad variable name in Python
... keyword or built-in function in any language is a bad idea, even if it is allowed.
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Mercurial .hgignore for Visual Studio 2008 projects
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Here's my standard .hgignore file for use with VS2008 that was originally modified from a Git ignore file:
# Ignore file for Visual Studio 2008
# use glob syntax
syntax: glob
# Ignore Visual Studio 2008 files
*.obj
*.exe
*.pdb
*.user
*.aps
*.pch
*.vspscc
*_i.c
*_p.c
*.ncb
*.suo
*.tlb
*.tlh
...
How do you create a remote Git branch?
...
First, you create your branch locally:
git checkout -b <branch-name> # Create a new branch and check it out
The remote branch is automatically created when you push it to the remote server. So when you feel ready for it, you can just do:
git push &...
Django select only rows with duplicate field values
... syntax is also how Django interprets you wanting to do a join. So, essentially when you try to filter on that, Django thinks you're trying to do a join with count which obviously doesn't exist. The fix is to specify a name for your annotation result, i.e. annotate(mycount=Count('id')) and then filt...
Representing graphs (data structure) in Python
...f._graph[node2].add(node1)
def remove(self, node):
""" Remove all references to node """
for n, cxns in self._graph.items(): # python3: items(); python2: iteritems()
try:
cxns.remove(node)
except KeyError:
pass
tr...