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Python `if x is not None` or `if not x is None`?
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There's no performance difference, as they compile to the same bytecode:
Python 2.6.2 (r262:71600, Apr 15 2009, 07:20:39)
>>> import dis
>>> def f(x):
... return x is not None
...
>>> dis.dis(f)
2 0 LOAD_FAST 0 (x)
3 LOAD_CONST...
Why is parenthesis in print voluntary in Python 2.7?
In Python 2.7 both the following will do the same
4 Answers
4
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Python's time.clock() vs. time.time() accuracy?
Which is better to use for timing in Python? time.clock() or time.time()? Which one provides more accuracy?
16 Answers
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How do you read a file into a list in Python? [duplicate]
...en find the mean, standard deviation, etc. without using the easy built-in Python tools.
8 Answers
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Python Graph Library [closed]
I'm writing a python application that will make heavy use of a graph data structure. Nothing horribly complex, but I'm thinking some sort of graph/graph-algorithms library would help me out. I've googled around, but I don't find anything that particularly leaps out at me.
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Python, Unicode, and the Windows console
...y characters. What's the best way around this? Is there any way I can make Python automatically print a ? instead of failing in this situation?
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Python: List vs Dict for look up table
... true for very large sets/dicts. The worst case scenario according to wiki.python.org/moin/TimeComplexity is O(n). I guess it depends on the internal hashing implementation at what point the average time diverges from O(1) and starts converging on O(n). You can help the lookup performance by compart...
Accessing the index in 'for' loops?
...h you would normally use in languages such as C or PHP), is considered non-pythonic.
The better option is to use the built-in function enumerate(), available in both Python 2 and 3:
for idx, val in enumerate(ints):
print(idx, val)
Check out PEP 279 for more.
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How to read attribute value from XmlNode in C#?
Suppose I have a XmlNode and I want to get the value of an attribute named "Name".
How can I do that?
8 Answers
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What does the “at” (@) symbol do in Python?
I'm looking at some Python code which used the @ symbol, but I have no idea what it does. I also do not know what to search for as searching Python docs or Google does not return relevant results when the @ symbol is included.
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