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String concatenation: concat() vs “+” operator
...then throwing it away when you create the final String. In practice memory allocation is surprisingly fast.
Update: As Pawel Adamski notes, performance has changed in more recent HotSpot. javac still produces exactly the same code, but the bytecode compiler cheats. Simple testing entirely fails bec...
Best practices for adding .gitignore file for Python projects? [closed]
...uildout I have following in .gitignore (along with *.pyo and *.pyc):
.installed.cfg
bin
develop-eggs
dist
downloads
eggs
parts
src/*.egg-info
lib
lib64
Thanks to Jacob Kaplan-Moss
Also I tend to put .svn in since we use several SCM-s where I work.
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Why dict.get(key) instead of dict[key]?
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It allows you to provide a default value if the key is missing:
dictionary.get("bogus", default_value)
returns default_value (whatever you choose it to be), whereas
dictionary["bogus"]
would raise a KeyError.
If omitted...
SQLAlchemy: cascade delete
...use that is where you defined your relationship (it doesn't care that you called it "Child" of course).
If you define the relationship on the Parent class instead, it will work:
children = relationship("Child", cascade="all,delete", backref="parent")
(note "Child" as a string: this is allowed wh...
What's the meaning of exception code “EXC_I386_GPFLT”?
...hich is the x86's way to tell you that "you did something that you are not allowed to do". It typically DOESN'T mean that you access out of memory bounds, but it could be that your code is going out of bounds and causing bad code/data to be used in a way that makes for an protection violation of som...
php $_POST array empty upon form submission
... "WWW." The $_POST array was getting emptied in the process. So to fix it all I had to do was submit to www.domain.com
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How to use a dot “.” to access members of dictionary?
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Install dotmap via pip
pip install dotmap
It does everything you want it to do and subclasses dict, so it operates like a normal dictionary:
from dotmap import DotMap
m = DotMap()
m.hello = 'world'
m.hello
m.hello += '!'
# m...
Why would one use nested classes in C++?
... it at any time so you can not use it.
Look at std::list or std::map they all contain hidden classes (or do they?). The point is they may or may not, but because the implementation is private and hidden the builders of the STL were able to update the code without affecting how you used the code, or...
How do I implement __getattribute__ without an infinite recursion error?
I want to override access to one variable in a class, but return all others normally. How do I accomplish this with __getattribute__ ?
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How to request Administrator access inside a batch file
...s method doesn't forward arguments. Do you know How that can be done? Basically what I observe is that on the first line %1 has some value and on the last line %1 is null. I need to forward the arguments.
– prongs
Jan 11 '13 at 11:54
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