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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
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>>> dis.dis(f)
2 0 LOAD_FAST 0 (x)
3 LOAD_CONST...
Get: TypeError: 'dict_values' object does not support indexing when using python 3.2.3 [duplicate]
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In Python 3, dict.values() (along with dict.keys() and dict.items()) returns a view, rather than a list. See the documentation here. You therefore need to wrap your call to dict.values() in a call to list like so:
v = list(d.va...
Check if directory mounted with bash
... even tell you it's not mounted, although mount said it was. HUGE flaw in linux file system.
– Dev Null
Dec 3 '13 at 16:00
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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, 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 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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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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Accessing class variables from a list comprehension in the class definition
... a list comprehension within the class definition? The following works in Python 2 but fails in Python 3:
5 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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How can I view all the git repositories on my machine?
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If you are in Linux find / -name ".git", otherwise there is no way, they are standard directories, just use your OS file/folder find program to find .git named folders.
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