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Representing graphs (data structure) in Python
...f._graph[node2].add(node1)
def remove(self, node):
""" Remove all references to node """
for n, cxns in self._graph.items(): # python3: items(); python2: iteritems()
try:
cxns.remove(node)
except KeyError:
pass
tr...
Can modules have properties the same way that objects can?
...s? When I put this code in one file x.py and import it from another, then calling x.y results in AttributeError: 'NoneType' object has no attribute 'c', since _M somehow has value None...
– Stephan202
May 19 '09 at 1:35
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Stripping everything but alphanumeric chars from a string in Python
What is the best way to strip all non alphanumeric characters from a string, using Python?
11 Answers
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Installing Google Protocol Buffers on mac
I would like to install the older version of Google Protocol Buffers (protobuf-2.4.1) on mac using Terminal command line. I tried with brew install protobuf , but the latest version 2.5.0 has been installed. Is it possible to install the older version from terminal.
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How to check if all elements of a list matches a condition?
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The best answer here is to use all(), which is the builtin for this situation. We combine this with a generator expression to produce the result you want cleanly and efficiently. For example:
>>> items = [[1, 2, 0], [1, 2, 0], [1, 2, 0]]
>>...
Creating a blocking Queue in .NET?
...threads reading from the same queue. If the queue reaches a specific size all threads that are filling the queue will be blocked on add until an item is removed from the queue.
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What does $_ mean in PowerShell?
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This is the variable for the current value in the pipe line, which is called $PSItem in Powershell 3 and newer.
1,2,3 | %{ write-host $_ }
or
1,2,3 | %{ write-host $PSItem }
For example in the above code the %{} block is called for every value in the array. The $_ or $PSItem variable ...
Why is it slower to iterate over a small string than a small list?
...nd with timeit and noticed that doing a simple list comprehension over a small string took longer than doing the same operation on a list of small single character strings. Any explanation? It's almost 1.35 times as much time.
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Forced naming of parameters in Python
...(10, forcenamed=20)
10 20
>>> foo(10, 20)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: foo() takes exactly 1 positional argument (2 given)
This can also be combined with **kwargs:
def foo(pos, *, forcenamed, **kwargs):
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How can I filter a date of a DateTimeField in Django?
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Much better than all of the other answers here, thanks!
– Kin
Jan 6 '14 at 17:06
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