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How to override the [] operator in Python?
...rwise this will happen:
>>> myobj[5] = 1
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: MyClass instance has no attribute '__setitem__'
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How to check if a python module exists without importing it
...ING
When trying to find a submodule, it will import the parent module (for all of the above methods)!
food/
|- __init__.py
|- eggs.py
## __init__.py
print("module food loaded")
## eggs.py
print("module eggs")
were you then to run
>>> import importlib
>>> spam_spec = importli...
Iterate an iterator by chunks (of n) in Python? [duplicate]
...y_list[i:i + chunk_size] for i in range(0, len(my_list), chunk_size)]
Finally, a solution that works on general iterators an behaves as desired is
def grouper(n, iterable):
it = iter(iterable)
while True:
chunk = tuple(itertools.islice(it, n))
if not chunk:
return...
After Installing Java JDK 7 For Mac OS X - mvn -version still shows java version 1.6.0_31
Oracle released Java JDK 7 on April 26 for Mac OS X. I followed the install instructions and when I do java -version in a terminal window I get:
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What is a plain English explanation of “Big O” notation?
...a notation "Θ" (which is a two-side bound). In my experience, this is actually typical of discussions in non-academic settings. Apologies for any confusion caused.
Big O complexity can be visualized with this graph:
The simplest definition I can give for Big-O notation is this:
Big-O notation is ...
unit testing of private functions with mocha and node.js
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If the function is not exported by the module, it cannot be called by test code outside the module. That's due to how JavaScript works, and Mocha cannot by itself circumvent this.
In the few instances where I determined that testing a private function is the right thing to do, what I'...
Mismatched anonymous define() module
I'm getting this error when I browse my webapp for the first time (usually in a browser with disabled cache).
7 Answers
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List all sequences in a Postgres db 8.1 with SQL
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The following query gives names of all sequences.
SELECT c.relname FROM pg_class c WHERE c.relkind = 'S';
Typically a sequence is named as ${table}_id_seq. Simple regex pattern matching will give you the table name.
To get last value of a sequence use the ...
In C#, should I use string.Empty or String.Empty or “” to intitialize a string?
...person - so I suggest you find out what most people on your team like, and all go with that for consistency. Personally I find "" easier to read.
The argument that "" and " " are easily mistaken for each other doesn't really wash with me. Unless you're using a proportional font (and I haven't worke...
How to upload a file in Django? [closed]
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Phew, Django documentation really does not have good example about this. I spent over 2 hours to dig up all the pieces to understand how this works. With that knowledge I implemented a project that makes possible to upload files and show them as list. To...