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Length of generator output [duplicate]
Python provides a nice method for getting length of an eager iterable, len(x) that is. But I couldn't find anything similar for lazy iterables represented by generator comprehensions and functions. Of course, it is not hard to write something like:
...
How do I get Flask to run on port 80?
...hat error message because you have apache2 running on port 80.
If this is for development, I would just leave it as it is on port 5000.
If it's for production either:
Not Recommended
Stop apache2 first;
Not recommended as it states in the documentation:
You can use the builtin server dur...
How to create module-wide variables in Python? [duplicate]
...iables are local. You simply add a global declaration in your function, before you try to use the global.
def initDB(name):
global __DBNAME__ # add this line!
if __DBNAME__ is None: # see notes below; explicit test for None
__DBNAME__ = name
else:
raise RuntimeError("D...
Standard alternative to GCC's ##__VA_ARGS__ trick?
There is a well-known problem with empty args for variadic macros in C99.
10 Answers
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Execution of Python code with -m option or not
...n you use the -m command-line flag, Python will import a module or package for you, then run it as a script. When you don't use the -m flag, the file you named is run as just a script.
The distinction is important when you try to run a package. There is a big difference between:
python foo/bar/baz.p...
Performance difference for control structures 'for' and 'foreach' in C#
Which code snippet will give better performance? The below code segments were written in C#.
9 Answers
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How to use Sphinx's autodoc to document a class's __init__(self) method?
Sphinx doesn't generate docs for __init__(self) by default. I have tried the following:
5 Answers
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Difference between __getattr__ vs __getattribute__
..._ is only invoked if the attribute wasn't found the usual ways. It's good for implementing a fallback for missing attributes, and is probably the one of two you want.
__getattribute__ is invoked before looking at the actual attributes on the object, and so can be tricky to implement correctly. Yo...
How to watch for array changes?
...hod
Going the quick and dirty route, you could override the push() method for your array1:
Object.defineProperty(myArray, "push", {
enumerable: false, // hide from for...in
configurable: false, // prevent further meddling...
writable: false, // see above ^
value: function () {
for (var...
Set Django IntegerField by choices=… name
... FWIW, if you need set it from a literal string (perhaps from a form, user input, or similar) you can then just do: thing.priority = getattr(thing, strvalue.upper()).
– mrooney
Feb 24 '13 at 23:22
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